Light emission reducing compounds for electronic devices

ABSTRACT

Double-notch filters for electronic devices are provided that filter light from both the blue spectrum as well as the red spectrum in narrow wavelength bands, or “notches.” A double-notch filter can, using input light from a conventional LED-backlit LCD display, output light that can be measured as substantially satisfying criteria for a D65 white point. In some examples, a double-notch filter can output light that can be measured as nearly satisfying criteria for a D65 white point, to within +/− 500 Kelvin. In some examples, a double-notch filter can output light that can be measured as nearly satisfying criteria for a D65 white point, to within +/− 1000 Kelvin.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. Nonprovisionalapplication Ser. No. 14/719,604, filed May 22, 2015 and titled LIGHTEMISSION REDUCING FILM FOR ELECTRONIC DEVICES, which claims the benefitof U.S. Provisional Application No. 62/002,412, filed May 23, 2014 andtitled LIGHT EMISSION REDUCING FILM FOR ELECTRONIC DEVICES. Thisapplication claims the benefit of U.S. Provisional Application No.62/421,578, filed Nov. 14, 2016 and titled LIGHT EMISSION REDUCINGCOMPOUNDS FOR ELECTRONIC DEVICES.

This application is related to U.S. Provisional Application No.62/175,926, filed Jun. 15, 2015 and titled LIGHT EMISSION REDUCING FILMFOR ELECTRONIC DEVICES, U.S. Provisional Application No. 62/254,871,filed Nov. 13, 2015 and titled LIGHT EMISSION REDUCING COMPOUNDS FORELECTRONIC DEVICES, U.S. Provisional Application No. 62/255,287, filedNov. 13, 2015 and titled LIGHT EMISSION REDUCING FILM FOR VIRTUALREALITY HEADSET, U.S. Provisional Application No. 62/322,624, filed Apr.14, 2016 and titled LIGHT EMISSION REDUCING FILM FOR ELECTRONIC DEVICES,International Application under the Patent Cooperation Treaty No.PCT/US2015/032175, filed May 22, 2015 and titled LIGHT EMISSION REDUCINGFILM FOR ELECTRONIC DEVICES, International Application under the PatentCooperation Treaty No. PCT/US2016/037457, filed Jun. 14, 2016 and titledLIGHT EMISSION REDUCING COMPOUNDS FOR ELECTRONIC DEVICES, and any otherU.S., International, or national phase patent applications stemming fromthe aforementioned applications.

The aforementioned patent applications are hereby incorporated byreference, such incorporation being limited such that no subject matteris incorporated that is contrary to the explicit disclosure herein. Anyincorporation by reference of documents above is further limited suchthat no claims included in the documents are incorporated by referenceherein. Any incorporation by reference of documents above is yet furtherlimited such that any definitions provided in the documents are notincorporated by reference herein unless expressly included herein.

FIELD OF THE TECHNOLOGY

The present disclosure relates to absorbing compound or compounds thatcan be placed on or incorporated into an electronic device, includingthe display screen of an electronic device.

BACKGROUND

Electronic digital devices typically emit a spectrum of light,consisting of rays of varying wavelengths, of which the human eye isable to detect a visible spectrum between about 350 to about 700nanometers (nm). It has been appreciated that certain characteristics ofthis light, both in the visible and nonvisible ranges, may be harmful tothe user, and lead to health symptoms and adverse health reactions, suchas, but not limited to, eyestrain, dry and irritated eyes, fatigue,blurry vision and headaches. There may be a link between exposure to theblue light found in electronic devices and human health hazards,particularly with potentially harmful risks for the eye. Some believethat exposure to the blue light and/or high energy visible light, suchas that emitted by screens of digital devices could lead to age-relatedmacular degeneration, decreased melatonin levels, acute retinal injury,accelerated aging of the retina, and disruption of cardiac rhythms,among other issues. Additional research may reveal additionalmusculoskeletal issues that result from prolonged exposure to the bluelight spectrum.

More specifically, high energy visible (HEV) light emitted by digitaldevices is known to increase eye strain more than other wavelengths inthe visible light spectrum. Blue light can reach deeper into the eyethan, for example, ultraviolet light and may cause damage to the retina.Additionally, there may also be a causal link between blue lightexposure and the development of Age-related Macular Degeneration (AMD)and cataracts. Additionally, the use of digital electronic devices isknown to cause eye strain symptoms. The damage is thought to be causedby HEV light that penetrates the macular pigment, causing more rapidretinal changes.

Additionally, blue light exposure suppresses melatonin for about twiceas long as green light and shifts circadian rhythms by twice as much.Blue wavelengths of light seem to be the most disruptive at night.Studies have also shown that blue light frequencies, similar to thosegenerated by LEDs from electronic devices, such as smart phones, are 50to 80 times more efficient in causing photoreceptor death than greenlight. Exposure to the blue light spectrum seem to accelerate AMD morethan other areas of the visible light spectrum. However, it is alsosuspected that exposure to the red and green light spectrums may alsopresent health risks, which can be mitigated by absorption of lightproduced by devices in that wavelength range.

Further, ultraviolet A (UVA) light (in the 320-380 nm range) is ofparticular concern to eye care professionals. UVA light is considered tobe damaging because it directly affects the crystalline lens of thehuman eye. In one embodiment, the film 200 reduces the High EnergyVisible light in accordance with the standards set by the InternationalSafety Equipment Association, specifically the ANSI/ISEA Z87.1-2010standard, which weighs the spectral sensitivity of the eye against thespectral emittance from the 380-1400 nm range.

Although the light generated by LEDs from digital devices appears normalto human vision, a strong peak of blue light ranging from 380-500nanometers is also emitted within the white light spectrum produced bythe screens of such digital devices. As this blue light corresponds to aknown spectrum for retinal hazards, a means for protecting users fromexposure to such light is needed.

Optical filters are used in a wide range of applications including lightfilters for LCD (Liquid Crystal Display) retardation films. LCDretardation films use alternate layers of materials comprised of anelectroplated pigment, pigment impregnated or a printing methodmaterials. These methods are compromised when they experience friction,heat or moisture and may cause a ghosting effect. Optical densitytransmissivity and sustainability requirements may also fail due tomoisture and mechanical integrity.

While some measures have been taken to reduce exposure to these harmfulrays, these measure have been inadequate. Some measures have implementedsoftware solutions to decrease the wavelengths emitted, but they areeasily altered to be less effective and can change the viewingexperience by blocking too much light from a chosen wavelength and,therefore, changing the colors viewable to a user. Other measures haveimplemented physical devices that are placed over screens. However,these devices severely alter the colors viewable to a user and, in mostcases, completely block at least one entire color from the colorspectrum.

More specifically, current film substrate technologies often lackdesired optical properties such as stability to UV light, selectivetransmissivity in the visible range, and absorption in the UV and highintensity blue light range, or other absorption characteristics. Currentfilm substrates also lack the desired mechanical properties such as heatresistance and mechanical robustness at the desired thinness. Glass,polycarbonate, acrylic, and nylon lenses and films exist, but may beunable to sustain dye or pigment dispersion and achieve an opticaldensity sufficient to maintain the high transmission values at thisthickness. In one embodiment, an F700 film, such as that produced byKentek Corporation, is resistant to moisture and humidity. Such a filmis preferable to glass, which may require re-polishing. Increased colorresolution, repeatability and the lack of a binder agent requirement areother benefits.

SUMMARY

In this disclosure, we describe concepts for double-notch filters forelectronic devices that filter light from both the blue spectrum as wellas the red spectrum in narrow wavelength bands, or “notches.” A singlenotch blue filtering/absorbing filter, by removing blue light, can causethe resulting filtered light to shift to a lower color temperature(compared to the spectrum of light input to the filter). This can beundesirable for at least color management reasons. By also removing anarrow-band portion of light in a red part of the spectrum, the colortemperature can be shifted back to a higher value, which may be moredesirable for color management.

In some examples, a double-notch filter can, using input light from aconventional LED-backlit LCD display, output light that can be measuredas substantially satisfying criteria for a D65 white point. In someexamples, a double-notch filter can output light that can be measured asnearly satisfying criteria for a D65 white point, to within +/− 500Kelvin. In some examples, a double-notch filter can output light thatcan be measured as nearly satisfying criteria for a D65 white point, towithin +/− 1000 Kelvin.

The above summary is not intended to describe each and every example orevery implementation of the disclosure. The Description that followsmore particularly exemplifies various illustrative embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates a light absorbent film according to one embodimentof the present disclosure.

FIG. 1B illustrates a light absorbent film according to one embodimentof the present disclosure.

FIG. 1C illustrates a light absorbent film according to one embodimentof the present disclosure.

FIG. 1D illustrates a transmission curve for a light absorbent filmaccording to one embodiment of the present disclosure.

FIG. 1E illustrates a transmission curve for a light absorbent filmaccording to one embodiment of the present disclosure.

FIG. 2A illustrates an exemplary interaction between an eye and a devicewith a light absorbent film according to one embodiment of the presentdisclosure.

FIG. 2B illustrates exemplary effectiveness wavelength absorbance rangesfor light absorbent films.

FIG. 2C-1 illustrates a plurality of absorbing compounds that may beutilized to achieve the desired characteristics of one embodiment of alight absorbent film.

FIG. 2C-2 illustrates a plurality of absorbing compounds that may beutilized to achieve the desired characteristics of one embodiment of alight absorbent film.

FIG. 2C-3 illustrates a plurality of absorbing compounds that may beutilized to achieve the desired characteristics of one embodiment of alight absorbent film.

FIG. 2C-4 illustrates a plurality of absorbing compounds that may beutilized to achieve the desired characteristics of one embodiment of alight absorbent film.

FIG. 2C-5 illustrates a plurality of absorbing compounds that may beutilized to achieve the desired characteristics of one embodiment of alight absorbent film.

FIG. 2C-6 illustrates a plurality of absorbing compounds that may beutilized to achieve the desired characteristics of one embodiment of alight absorbent film.

FIG. 2C-7 illustrates a plurality of absorbing compounds that may beutilized to achieve the desired characteristics of one embodiment of alight absorbent film.

FIG. 3A depicts a graph illustrating transmission as a function ofwavelength for a variety of absorbent films according to one embodimentof the present disclosure.

FIG. 4A depicts a method for generating a light-absorbing film for adevice according to one embodiment of the present disclosure.

FIG. 4B depicts a method for generating a light-absorbing film for adevice according to one embodiment of the present disclosure.

FIG. 4C depicts a method for generating a light-absorbing film for adevice according to one embodiment of the present disclosure.

FIG. 5A depicts an exploded view of the screen of an electronic devicecomprised of several layers of glass and/or plastic.

FIG. 5B depicts the screen of an electronic device comprised of severallayers of glass and/or plastic.

FIG. 5C depicts an exploded view of the screen of an electronic devicecomprised of several layers of glass and/or plastic with an absorbingfilm layer inserted between two of the several layers.

FIG. 5D depicts the screen of an electronic device comprised of severallayers of glass and/or plastic with an absorbing film layer insertedbetween two of the several layers.

FIG. 5E depicts an exploded view of the screen of an electronic devicecomprised of several layers of glass and/or plastic wherein alight-absorbing adhesive is added to one of the several layers.

FIG. 5F depicts the screen of an electronic device comprised of severallayers of glass and/or plastic wherein a light-absorbing coating isadded to one of the several layers.

FIG. 5G depicts light waves emitted from the screen of an electronicdevice comprised of several layers of glass and/or plastic.

FIG. 5H depicts light waves emitted from, and blocked by, the screen ofan electronic device comprised of several layers of glass and/or plasticwith an absorbing film layer inserted between two of the several layers.

FIG. 6A depicts a virtual reality headset with one embodiment of alight-absorbing layer inserted within the virtual reality headset.

FIG. 6B depicts a virtual reality headset with one embodiment of alight-absorbing layer inserted within the virtual reality headset.

FIG. 6C depicts a virtual reality headset with one embodiment of alight-absorbing layer inserted within the virtual reality headset.

FIG. 7 is a schematic cross-sectional view of an example display systemwith which systems of the present disclosure may be beneficiallyemployed.

FIG. 8 shows spectra for changing concentrations of a narrow notch bluelight filtering dye of the present disclosure.

FIG. 9 illustrates the effects of varying concentrations of colorcorrection dye.

FIG. 10 illustrates the effects of varying concentrations of a broadband blue absorption dye, without a color correction dye.

FIG. 11 illustrates color correction optimization trials for an LEDbacklight.

DETAILED DESCRIPTION

Generally, the present disclosure relates to an absorbing compound orcompounds that can be combined with one or more polymer substrates to beplaced on or incorporated into an electronic device. The absorbingcompound is, ideally, blue-based and provides protection to anindividual from the potentially harmful light emitted by the electronicdevice, and the polymer substrates are used for application to or in theelectronic device. The absorbing compound and polymer substratecombinations described herein can include material for making opticalfilters with defined transmission and optical density characteristicsfor visible wavelength transmissivity. The material to make suchfilters, in some embodiments, can include an organic dye impregnatedpolycarbonate composition. In application, the protective film can beapplied to a device's screen surface after purchase of the electronicdevice or the protective film can be incorporated into the screen duringproduction. In a further embodiment, the absorbing compound can beapplied as a protective coating layer to an existing film layer or othersubstrate in a device screen.

Film and Film Properties

FIGS. 1A-1C illustrate an exemplary film that is useful in oneembodiment of the present disclosure to absorb specific wavelengths oflight. A plurality of film materials may be appropriate, as described inany of the embodiments included below. A film material may be chosen fora specific application based on a variety of properties. For example, afilm material may be chosen for a specific hardness, scratch resistance,transparency, conductivity, etc. In one embodiment, the film iscomprised of at least one absorbing compound and from a polymermaterial, such as any one or more of the polymer bases listed below inTable 1. As mentioned above, the polymer bases are chosen based on thetype of technology the absorbing compounds are being applied to.

TABLE 1 POLYMER BASES FOR ABSORBANCE FILM Polymer base CharacteristicsAcrylic impact modified, chemical resistance, superb weatherability, UVresistance and transparency Epoxy Resistivity to energy and heatPolyamide Thermoformabilty, abrasion resistance, good mechanicalproperties; High tensile strength and elastic modulus, impact and crackresistance Polycarbonate Impact strength even at low temperatures.dimensional stability, weather resistance, UV resistance, flameretardant, super-weather resistance and heat stability, opticalproperties Polyester Optics, mechanical Strength, Solvent Resistant,Tear and puncture resistant Co-polyester (PETG, printable, scratchhardness PCTG) Polyethylene Geomembrane windows, global recylability,good moisture barrier, clarity, strength, toughness Polyolefin Goodchemical resistance Polypropylene High impact and puncture resistance,excellent extensibility Polystyrene good printablity, high impactresistance, good dimensional stability, easy to thermoform Polysolfonehigh strength, amorphous thermoplastic, clarity and toughness, high-heat deflection temperature, excellent thermal stability, excellenthydrolitic stability Polyurethane Excellent laminated transparency,microbial resistance, UV stability, contains adhesion promoter, mediumDurometer, Medium Modulus, Excellent Cold impact Polyvinyl ChlorideWeathering resistance, abrasion resistance, chemical resistance, flowcharacteristics, stable electrical properties Styrene Acrylonitrilesuperior mechanical strength, chemical resistance, heat resistance,durability, simplicity of production, recyclability, impact strength,heat resistance, good impact resistance, excellent hygiene, sanitationand safety benefits.

In one embodiment, any one or more of the polymers listed in Table 1 iscombined with one or more absorbing compounds, for example those listedbelow in Table 2, to generate a film 100 that can be utilized with oneor more devices, for example smartphones, laptops, tablets, glasses, orany other transparent surface utilized with an electronic displaydevice. In one embodiment, the polymer base for the film 100 is chosen,at least in part, based on transparency, such that a user can still viewa screen of an electronic display device through the film 100. Inanother embodiment, the polymer base is chosen, at least in part, basedon its compatibility with a desired absorbing compound. In furtherembodiments, the polymer base is chosen based on the substrate to whichthe absorbing compound is incorporate in or attached to.

In accordance with one embodiment, as shown in FIG. 1A, a film 100 isapplied to a device 102 with a screen 104. While FIG. 1A shows thedevice 102 as a smartphone, the film 100 can illustratively be designedto be applied to any other device, such as, for example the laptop 152with film 150 over screen 154 shown in FIG. 1B. Additionally, in anotherembodiment, the film 100 could be incorporated into a layer of a device,such as a contact lens or lenses of a pair of glasses.

Film 100 is formed of a suitable material, such as a polymer, and one ormore light absorption dyes that selectively reduce the peaks and slopesof electromagnetic emission from occupational and personal electronicdevices. Other examples of electronic devices with which such a film maybe used may include for example, LEDs, LCDs, computer monitors,equipment screens, televisions, tablets, cellular phones, etc. However,it could also be used on the user-end of a viewing experience, forexample incorporated into contact lenses or glasses.

FIG. 1C illustrates two layers of a film 100. In one embodiment, thefilm includes no antiglare coating as shown by film 170. In anotherembodiment, the film 100 includes a coating 172, wherein the coating 172comprises an antiglare coating 172, a hard coating 172, and/or a tackcoating 172. In one embodiment, the absorbing compound may beincorporated into the coating material directly, instead of the basefilm layer. This may be done, for example, due to compatibility betweenthe absorbing compound and the desired polymer substrate.

The film 100, in one embodiment, is blue-based and has a slight colortint, as a result at least in part of the absorbing compound selected,and works as a filter to reduce light emission from the screen 104. Inone embodiment, under a CIE light source D65, a film 100 having a 7.75mil thickness is a light blue-green color with (L, a, b) values of(90.24, −12.64, 3.54) with X-Y-Z values of (67.14, 76.83,78.90)respectively. In another embodiment, the film 100 appears lighter due toreduced loading.

In one embodiment, film 100 is configured to reduce light emissionacross a broad spectrum of light, for example, the 200 nm to the 3000 nmrange. In another example, film 100 can be configured to reduce lightemission in only a portion of this broad spectrum, for example, onlywithin the visible spectrum 390 nm to 700 nm, or only within a portionof the visible spectrum, such as within the spectrum 200 nm to 1400 nm.

In one embodiment, film 100 is configured to normalize the lightemission from screen 104 such that peaks of light intensity across thespectrum are reduced. In one example, the light emission intensity isnormalized to a maximum absorbance level between 0.0035 and 0.0038.

In the illustrated embodiment of FIG. 1A, film 100 is configured for usewith devices having touch screens (e.g. a capacitive touch screen). Whenused with a capacitive touch screen, such as screen 104, film 100 may beconfigured to have suitable electrical properties such that the usertouch inputs are accurately registered by the device. For example, film100 may have a dielectric constant that is less than 4. In anotherexample, the dielectric constant is less than 3. In one particularembodiment, the dielectric constant of film 100 is between 2.2 and 2.5.

In one embodiment, film 100 has a thickness between 10-30 mil and ahardness above 30 Rockwell R. In one embodiment, the hardness of film100 is between 45-125 Rockwell R.

While embodiments shown in FIGS. 1A-1C are described in the context of afilm applied to an electronic device after manufacture, it is noted thatthe described features can be used in other applications, such as, butnot limited to, application to eye wear (e.g. glasses, contacts, etc.)as well as applications on windows, for example, to protect againstlasers. It may also be used on any other surface through which light istransmitted and may be received by a human eye. In one embodiment, film100 is applied to eyewear lenses, such as corrective lens glasses,sunglasses, safety glasses, etc. While the film 100 is shown in FIGS. 1Aand 1B as being applied as an aftermarket feature to a device 102, andprovided to a user as shown in FIG. 1C, in another embodiment, the film100 is included within a device 102 during a manufacture of the device102 such that the film 100 is located behind a screen 104 or comprisesthe screen 104 of the device 102.

FIGS. 1D-1E illustrate a plurality of transmission curves for differentfilms that may be useful in embodiments of the present disclosure. Thetransmission characteristics of a film, for example film 100, may bedefined by a transmission curve, such as those shown in FIG. 1D or 1E.Specifically, curve 180 illustrates an exemplary transmission curve offilter glass. Curve 182 illustrates an exemplary transmission curve of afilm 100 with a thickness of 4 mil. Curve 184 illustrates an exemplarytransmission curve for a film 100 with a thickness of 7.75 mil. Thetransmission curve includes a transmission local maximum in a visiblelight wavelength range and a first and second transmission localminimums proximate each end of the visible light wavelength range.

In one embodiment, the transmission local maximum is at a locationbetween 575 nm and 425 nm, the first transmission local minimum being ator around a location of about 700 nm or greater, and the secondtransmission local minimum being at or around a location of about 300 nmor less. The transmission local maximum may have a transmission of 85%or greater. The transmission local maximum may further have atransmission of 90% or greater. The first and second transmission localminimums may have a transmission of less than 30%, in one embodiment. Inanother embodiment, the first and second transmission local minimums mayhave a transmission of less than 5%. The transmission curve, in oneembodiment, may also include a first and second 50% transmission cutoffbetween the respective transmission local minimums and the transmissionlocal maximum.

The transmission curve may also include, in one embodiment, a curveshoulder formed by a reduced slope for at least of the transmissioncurve between 750 nm and 575 nm, which increases transmission forwavelengths at this end of the visible spectrum (e.g. red light). In oneembodiment, the curve shoulder passes through a location at 644 nm±10nm. In other embodiments, the curve shoulder may pass through a locationat 580 nm±10 nm. One of the 50% transmission cutoffs may coincide withthe curve shoulder, for example, at 644 nm±10 nm.

As used herein, the terms “optical density” and “absorbance” may be usedinterchangeably to refer to a logarithmic ratio of the amount ofelectromagnetic radiation incident on a material to the amount ofelectromagnetic radiation transmitted through the material. As usedherein, “transmission” or “transmissivity” or “transmittance” may beused interchangeably to refer to the fraction or percentage of incidentelectromagnetic radiation at a specified wavelength that passes througha material. As used herein, “transmission curve” refers to the percenttransmission of light through an optical filter as a function ofwavelength. “Transmission local maximum” refers to a location on thecurve (i.e. at least one point) at which the transmission of lightthrough the optical filter is at a maximum value relative to adjacentlocations on the curve. “Transmission local minimum” refers to alocation on the curve at which transmission is at a minimum valuerelative to adjacent locations on the curve. As used herein, “50%transmission cutoff” refers to a location on the transmission curvewhere the transmission of electromagnetic radiation (e.g. light) throughthe optical filter is about 50%.

In one embodiment, the transmission characteristics of the opticalfilters, for example those shown in FIG. 3 below, may be achieved, inone embodiment, by using a polycarbonate film as a polymer substrate,with a blue or blue-green organic dye dispersed therein. The organic dyeimpregnated polycarbonate film may have a thickness less than 0.3 mm. Inanother embodiment, the polycarbonate film may have a thickness lessthan 0.1 mm. The thinness of the polycarbonate film may facilitate themaximum transmission of greater than 90% of light produced by a device.In at least one embodiment, the organic dye impregnated film may have athickness between 2.5 mils-14 mils. The combination of the polycarbonatesubstrate and the blue or blue-green organic dye is used in one or moreembodiments of the present disclosure to provide improved heat resistantand mechanical robustness even with the reduced thickness.

The polycarbonate film may include any type of optical gradepolycarbonate such as, for example, LEXAN 123 R. Although polycarbonateprovides desirable mechanical and optical properties for a thin film,other polymers may also be used such as a cyclic olefilm copolymer(COC).

In one embodiment, similar transmission characteristics may also beachieved, for example, by using an acrylic film with a blue-greenorganic dye dispersed therein. The organic dye impregnated acrylic filmmay have a thickness less than 0.3 mm. In another embodiment, theacrylic film may have a thickness less than 0.1 mm. The thinness of theacrylic film may facilitate the maximum transmission of greater than 90%of light produced by a device. In at least one embodiment, the organicdye impregnated film may have a thickness between 2.5 mils-14 mils. Thecombination of the acrylic substrate and the blue green organic dye maybe used, in one or more embodiments, to provide improved heat resistantand mechanical robustness even with the reduced thickness.

In another embodiment, similar transmission characteristics may also beachieved, for example, by using an epoxy film with a blue-green organicdye dispersed therein. The organic dye impregnated epoxy film may have athickness less than 0.1 mm. In another embodiment, the epoxy film mayhave a thickness less than 1 mil. The thinness of the epoxy film mayfacilitate the maximum transmission of greater than 90% of lightproduced by a device. The combination of the epoxy substrate and theblue green organic dye may be used, in one or more embodiments, toprovide improved heat resistant and mechanical robustness even with thereduced thickness.

In a further embodiment, similar transmission characteristics may alsobe achieved, for example, by using a PVC film with a blue-green organicdye dispersed therein. The organic dye impregnated PVC film may have athickness less than 0.1 mm. In another embodiment, the PVC film may havea thickness less than 1 mil. The thinness of the PVC film may facilitatethe maximum transmission of greater than 90% of light produced by adevice. The combination of the PVC substrate and the blue green organicdye may be used, in one or more embodiments, to provide improved heatresistant and mechanical robustness even with the reduced thickness.

The organic dye impregnated polycarbonate film may, in one embodiment,also have the desired optical characteristics at this reduced thicknesswith a parallelism of up to 25 arcseconds and a 0-30° chief ray ofincident angle. In a preferred embodiment, the angle of incidence iswithin the range of 0-26°. The organic dye impregnated polycarbonatefilm may further provide improved UV absorbance with an optical densityof greater than 5 in the UV range. The exemplary combination of apolycarbonate substrate with a blue-green dye is provided for examplepurposes only. It is to be understood that any of the absorbingcompounds described in detail below could be combined with any of thepolymer substrates described above to generate a film with the desiredmechanical properties and transmissivity.

Embodiments of the optical filter 100, as described herein, may be usedfor different applications including, without limitation, as a lightfilter to improve color rendering and digital imaging, an LCDretardation film with superior mechanical properties, an excellent UVabsorbance, a light emission reducing film for an electronic device toreduce potentially harmful wavelengths of light, and an opticallycorrect thin laser window with high laser protection values. In theseembodiments, the optical filter may be produced as a thin film with thedesired optical characteristics for each of the applications.

In some embodiments, the color rendering index (CRI) change resultingfrom transmission through embodiments of the present disclosure isminimal. For example, the difference in the CRI value before and afterapplication of embodiments of the present disclosure to an electronicdevice may be between one and three. Therefore, when embodiments of thepresent disclosure are applied to the display of an electronic device, auser viewing the display will see minimal, if any, change in color andall colors will remain visible.

Absorbance and Absorbing Materials

Absorbance of wavelengths of light occurs as light encounters acompound. Rays of light from a light source are associated with varyingwavelengths, where each wavelengths is associated with a differentenergies. When the light strikes the compound, energy from the light maypromote an electron within that compound to an anti-bonding orbital.This excitation occurs, primarily, when the energy associated with aparticular wavelength of light is sufficient to excite the electron and,thus, absorb the energy. Therefore, different compounds, with electronsin different configurations, absorb different wavelengths of light. Ingeneral, the larger the amount of energy required to excite an electron,the lower the wavelength of light required. Further, a single compoundmay absorb multiple wavelength ranges of light from a light source as asingle compound may have electrons present in a variety ofconfigurations.

FIG. 2A illustrates an exemplary interaction between a device and an eyewith an exemplary film that may be useful in one embodiment of thepresent disclosure. In one embodiment, the film 200 comprises a filmplaced on the device 202, for example as an after-market addition. Inanother embodiment, the film 200 comprises a portion of the device 202,for example the screen of device 202. In a further embodiment, the filmis a physical barrier worn on or near the eye 250, for example as acontact lens, or as part of the lenses of a pair of glasses; either asan after-market application or part of the lenses themselves.

As shown in FIG. 2A, device 202 produces a plurality of wavelengths oflight including, high intensity UV light 210, blue violet light 212,blue turquoise light 214 and visible light 218. High intensity UV lightmay comprise, in one embodiment, wavelengths of light in the 315-380 nmrange. Light in this wavelength range is known to possibly cause damageto the lens of an eye. In one embodiment, blue-violet light 212 maycomprise wavelengths of light in the 380-430 nm range, and is known topotentially cause age-related macular degeneration. Blue-turquoise light214 may comprise light in the 430-500 nm range and is known to affectthe sleep cycle and memory. Visible light 218 may also comprise otherwavelengths of light in the visible light spectrum.

As used herein, “visible light” or “visible wavelengths” refers to awavelength range between 380 to 750 nm. “Red light” or “red wavelengths”refers to a wavelength range between about 620 to 675 nm. “Orange light”or “orange wavelengths” refers to a wavelength range between about 590to 620 nm. “Yellow light” or “yellow wavelengths” refers to a wavelengthrange between about 570 to 590 nm. “Green light” or “green wavelengths”refers to a wavelength range between about 495 to 570 nm. “Blue light”or “blue wavelengths” refers to a wavelength range between about 450 to495 nm. “Violet light” or “violet wavelengths” refers to a wavelengthrange between about 380 to 450 nm. As used herein, “ultraviolet” or “UV”refers to a wavelength range that includes wavelengths below 350 nm, andas low as 10 nm. “Infrared” or “IR” refers to a wavelength range thatincludes wavelengths above 750 nm, and as high as 3,000 nm.

When a particular wavelength of light is absorbed by a compound, thecolor corresponding to that particular wavelength does not reach thehuman eye and, thus, is not seen. Therefore, for example, in order tofilter out UV light from a light source, a compound may be introducedinto a film that absorbs light with a wavelength below 350 nm. A list ofsome exemplary light-absorbing compounds for various ranges ofwavelengths are presented in Table 2 below, and correspond to exemplaryabsorption spectra illustrated in FIG. 2D. The absorbing materials usedin the present disclosure achieve protection for the individual whilesimultaneously leaving the color imagery of the device intact.Therefore, the absorbing compounds ideally block only a portion of thewavelength ranges for each color, so that each hue is still visible tothe individual viewing the screen of the electronic device. Further, thewavelength ranges that are blocked may be wavelength ranges for a colorthat are not visible to a person. Therefore, in some embodiments, thepresent disclosure provides a neutral density filter allowing for fullcolor recognition.

TABLE 2 ABSORBING MATERIALS AND WAVELENGTH RANGES Exemplary Polymer260-400 nm 400-700 nm Infrared Substrate Target Range Target RangeTarget Range Polycarbonate 1002 1004 1006 PVC 1008 1010 1020 Epoxy 10221018 1026 Polyester 1028 1024 1032 Polyethylene 1040 1030 1038 Polyamide1046 1036 1044 1042 1050 1048

In one embodiment, a film 200 is manufactured by choosing one of thesubstrates from the first column of Table 2, and selecting one absorbingcolumn from one or more of columns 2-4, depending on the wavelengthrange to be targeted for absorption. In an embodiment, a UV-targetingabsorbing compound is not needed when the polymer substrate contains aUV inhibitor, a UV stabilizer, or otherwise inherently possesses UVabsorbing properties. Absorbing compounds then can be selected from anyof the columns 2-4 for addition in order to increase absorption of lightproduced in the target wavelength ranges. Absorbing compounds can beselected in combination, provided that high transmission of light ismaintained, and the color tint is maintained, such that color integrityproduced by a device remains true. In one embodiment, the absorbingcompounds are provided in a polymer or pellet form and coextruded withthe polymer substrate to produce the film 200. In another embodiment,the absorbing compound is provided in a separate layer from the polymersubstrate, for example as a component in a coating layer applied to thepolymer substrate, or an additional scratch resistance layer.

Additionally, many of the exemplary compounds described in each ofcolumns 2, 3 and 4 can be substituted to produce the desiredcharacteristics in other polymer substrates. For example, while compound1002 is listed as an ideal compound for combination with a polycarbonatesubstrate, compound 1002 is also known as a compatible compound forimpregnation with PVC, acetals and cellulose esters. Some potentialexemplary combinations of the compounds and polymer substrates presentedin Table 2 are described in further detail in the examples below.However, it is to be understood that other possible combinations,including with polymer substrates listed in Table 1 and not presentedagain in Table 2, are possible.

In one embodiment, the organic dye dispersed in the polymer substrateprovides selective transmission characteristics including, for example,reducing transmissivity for blue light wavelengths and/or red lightwavelengths. The reduction of these unnaturally high emissivity levelsof a particular band or wavelength to a level more representative ofdaylight helps to decrease some of the undesirable effects of the use ofdigital electronic devices. In addition, the optical film may reduce theHEV light in the range that is emitted by a device 202. However, theoptical film 200 is, in one embodiment, also configured in order toallow other blue wavelengths of light, for example the color cyan,through in order to preserve color rendition by the device 202.

Polycarbonate Example

In one embodiment, the film 200 comprises a polycarbonate substrateimpregnated with an absorbing compound 1002 selected to target lightproduced in the 260-400 nm range. In one embodiment, absorbing compound1002, is selected for a peak absorption in the 300-400 nm range. Oneexemplary absorbing compound is, for example, Tinuvin®, provided by CibaSpecialty Chemicals, also known as 2-(2H-benzotriazol-2-yl)-p-cresol.However, any other exemplary absorbing compound with strong absorptioncharacteristics in the 300-400 nm range would also be suitable forabsorbing UV light. In an embodiment where Tinuvin® is utilized toprovide UV protection, other polymer substrates, such as those listed inTable 1, would also be suitable for the generation of film 200.

In one embodiment, the film 200 comprises a polycarbonate substrateimpregnated with an absorbing compound 1004 selected to target lightproduced in the 400-700 nm range. In one embodiment, absorbing compound1004 is selected for a peak absorption in the 400-700 nm range.Specifically, in one embodiment, absorbing compound 1004 is selected forpeak absorption in the 600-700 nm range. Even more specifically, in oneembodiment, absorbing compound is selected for peak absorption in the635-700 nm range. One exemplary absorbing compound is a proprietarycompound produced by Exciton®, with commercial name ABS 668. However,any other exemplary absorbing compound with strong absorption in the600-700 nm range of the visible spectrum may also be suitable for thegeneration of film 200. In another embodiment, compound 1004 may also becombined with a different polymer substrate from Table 1.

In one embodiment, the film 200 comprises a polycarbonate substrateimpregnated with an absorbing compound 1006 selected to target lightproduced in the infrared range. In one embodiment, absorbing compound1006 is selected to target light produced in the 800-1100 nm range.Specifically, in one embodiment, absorbing compound 1006 is selected fora peak absorption in the 900-1000 nm range. One exemplary compound maybe the NIR1002A dye produced by QCR Solutions Corporation. However, anyother exemplary absorbing compound with strong absorption in theinfrared range may also be suitable for the generation of film 200. Inanother embodiment, compound 1006 may also be combined with a differentpolymer substrate from Table 1.

In one embodiment, a polymer substrate is impregnated with a combinationof compounds 1002, 1004, and 1006 such that any two of compounds 1002,1004, and 1006 are both included to form film 200. In anotherembodiment, all three of compounds 1002, 1004, and 1006 are combinedwithin a polymer substrate to form film 200.

In another embodiment, the polycarbonate substrate is provided in a film200 along with any one of compounds 1002, 1008, 1022, 1028, 1040 or1046. This may be, in one embodiment, in combination with any one ofcompounds 1004, 1010, 1018, 1024, 1030, 1036, 1042 or 1048. This may be,in one embodiment, in combination with any one of compounds 1006, 1020,1026, 1032, 1038, 1044 or 1050.

PVC Filter Example

In one embodiment, the film 200 comprises a poly-vinyl chloride (PVC)substrate impregnated with an absorbing compound 1008 selected to targetlight produced in the 260-400 nm range. In one embodiment, absorbingcompound 1008, is selected for a peak absorption in the 320-380 nmrange. One exemplary absorbing compound is DYE VIS 347, produced by AdamGates & Company, LLC. However, any other exemplary absorbing compoundwith strong absorption characteristics in the 300-400 nm range wouldalso be suitable for absorbing UV light. In an embodiment where DYE VIS347 is utilized to provide UV protection, other polymer substrates, suchas those listed in Table 1, would also be suitable for the generation offilm 200.

In one embodiment, the film 200 comprises a PVC substrate impregnatedwith an absorbing compound 1010 selected to target light produced in the400-700 nm range. Specifically, in one embodiment, absorbing compound1010 is selected for peak absorption in the 550-700 nm range. Even morespecifically, in one embodiment, absorbing compound is selected for peakabsorption in the 600-675 nm range. One exemplary absorbing compound isADS640PP, produced by American Dye Source, Inc., also known as2-[5-(1,3-Dihydro-3,3-dimethyl-1-propyl-2H-indol-2-ylidene)-1,3-pentadienyl]-3,3-dimethyl-1-propyl-3H-indoliumperchlorate. However, any other exemplary absorbing compound with strongabsorption in the 600-700 nm range of the visible spectrum may also besuitable for the generation of film 200. In another embodiment, compound1010 may also be combined with a different polymer substrate from Table1.

In one embodiment, a polymer substrate is impregnated with a combinationof compounds 1008 and 1010. In another embodiment, the PVC substrate isprovided in a film 200 along with any one of compounds 1002, 1008, 1022,1028, 1040 or 1046. This may be, in one embodiment, in combination withany one of compounds 1004, 1010, 1018, 1024, 1030, 1036, 1042 or 1048.This may be, in one embodiment, in combination with any one of compounds1006, 1020, 1026, 1032, 1038, 1044 or 1050.

Epoxy Example

In one embodiment, the film 200 comprises an epoxy substrate impregnatedwith an absorbing compound 1016 selected to target light produced in the260-400 nm range. In one embodiment, absorbing compound 1016, isselected for a peak absorption in the 300-400 nm range. Specifically, inone embodiment, absorbing compound 1016 is selected for peak absorptionin the 375-410 range. One exemplary absorbing compound is, for example,ABS 400, produced by Exciton, with a peak absorbance at 399 nm. However,any other exemplary absorbing compound with strong absorptioncharacteristics in the 300-400 nm range would also be suitable forabsorbing UV light. In an embodiment where ABS 400 is utilized toprovide UV protection, other polymer substrates, such as those listed inTable 1, may also be suitable for the generation of film 200.

In one embodiment, the film 200 comprises an epoxy substrate impregnatedwith an absorbing compound 1018 selected to target light produced in the400-700 nm range. In one embodiment, absorbing compound 1018 is selectedfor a peak absorption in the 400-700 nm range. Specifically, in oneembodiment, absorbing compound 1018 is selected for peak absorption inthe 600-700 nm range. Even more specifically, in one embodiment,absorbing compound is selected for peak absorption in the 650-690 nmrange. One exemplary absorbing compound is a proprietary compoundproduced by QCR Solutions Corporation, with commercial name VIS675F andpeak absorption, in chloroform, at 675 nm. However, any other exemplaryabsorbing compound with strong absorption in the 600-700 nm range of thevisible spectrum may also be suitable for the generation of film 200. Inanother embodiment, compound 1018 may also be combined with a differentpolymer substrate from Table 1.

In one embodiment, the film 200 comprises an epoxy substrate impregnatedwith an absorbing compound 1020 selected to target light produced in theinfrared range. In one embodiment, absorbing compound 1020 is selectedto target light produced in the 800-1100 nm range. Specifically, in oneembodiment, absorbing compound 1020 is selected for a peak absorption inthe 900-1080 nm range. In one embodiment, absorbing compound is aproprietary compound produced by QCR Solutions Corporation, withcommercial name NIR1031M, and peak absorption, in acetone, at 1031 nm.However, any other exemplary absorbing compound with strong absorptionin the infrared range may also be suitable for the generation of film200. In another embodiment, compound 1020 may also be combined with adifferent polymer substrate from Table 1.

In one embodiment, a polymer substrate is impregnated with a combinationof compounds 1016, 1018, and 1020 such that any two of compounds 1016,1018, and 1020 are both included to form film 200. In anotherembodiment, all three of compounds 1016, 1018, and 1020 are combinedwithin a polymer substrate to form film 200.

In another embodiment, the epoxy substrate is provided in a film 200along with any one of compounds 1002, 1008, 1022, 1028, 1040 or 1046.This may be, in one embodiment, in combination with any one of compounds1004, 1010, 1018, 1024, 1030, 1036, 1042 or 1048. This may be, in oneembodiment, in combination with any one of compounds 1006, 1020, 1026,1032, 1038, 1044 or 1050.

Polyamide Example

In one embodiment, the film 200 comprises a polyamide substrateimpregnated with an absorbing compound 1022 selected to target lightproduced in the 260-400 nm range. In one embodiment, absorbing compound1022, is selected for a peak absorption in the 260-350 nm range. Oneexemplary absorbing compound is, for example, produced by QCR SolutionsCorporation with product name UV290A. However, any other exemplaryabsorbing compound 1022 with strong absorption characteristics in the260-400 nm range would also be suitable for absorbing UV light. In anembodiment where UV290A is utilized to provide UV protection, otherpolymer substrates, such as those listed in Table 1, would also besuitable for the generation of film 200.

In one embodiment, the film 200 comprises a polyamide substrateimpregnated with an absorbing compound 1024 selected to target lightproduced in the 400-700 nm range. In one embodiment, absorbing compound1024 is selected for a peak absorption in the 600-700 nm range.Specifically, in one embodiment, absorbing compound 1024 is selected forpeak absorption in the 620-700 nm range. One exemplary absorbingcompound is a proprietary compound produced by Adam Gates & Company, LLCwith product name DYE VIS 670, which also has an absorption peak between310 and 400 nm. However, any other exemplary absorbing compound withstrong absorption in the 600-700 nm range of the visible spectrum mayalso be suitable for the generation of film 200. In another embodiment,compound 1024 may also be combined with a different polymer substratefrom Table 1.

In one embodiment, the film 200 comprises a polyamide substrateimpregnated with an absorbing compound 1026 selected to target lightproduced in the infrared range. In one embodiment, absorbing compound1026 is selected to target light produced in the 800-1200 nm range.Specifically, in one embodiment, absorbing compound 1026 is selected fora peak absorption in the 900-1100 nm range. One exemplary absorbingcompound is a proprietary compound produced by QCR SolutionsCorporation, with product name NIR1072A, which has an absorbance peak at1072 nm in acetone. However, any other exemplary absorbing compound withstrong absorption in the infrared range may also be suitable for thegeneration of film 200. In another embodiment, compound 1026 may also becombined with a different polymer substrate from Table 1.

In one embodiment, a polymer substrate is impregnated with a combinationof compounds 1022, 1024, and 1026 such that any two of compounds 1022,1024, and 1026 are both included to form film 200. In anotherembodiment, all three of compounds 1022, 1024, and 1026 are combinedwithin a polymer substrate to form film 200.

In another embodiment, the polyamide substrate is provided in a film 200along with any one of compounds 1002, 1008, 1022, 1028, 1040 or 1046.This may be, in one embodiment, in combination with any one of compounds1004, 1010, 1018, 1024, 1030, 1036, 1042 or 1048. This may be, in oneembodiment, in combination with any one of compounds 1006, 1020, 1026,1032, 1038, 1044 or 1050.

Polyester Example

In one embodiment, the film 200 comprises a polyester substrateimpregnated with an absorbing compound 1036 selected to target lightproduced in the 400-700 nm range. In one embodiment, absorbing compound1036 is selected for a peak absorption in the 600-750 nm range.Specifically, in one embodiment, absorbing compound 1036 is selected forpeak absorption in the 670-720 nm range. One exemplary absorbingcompound is a proprietary compound produced by Exciton®, with commercialname ABS 691, which has an absorption peak at 696 nm in polycarbonate.However, any other exemplary absorbing compound with strong absorptionin the 600-700 nm range of the visible spectrum may also be suitable forthe generation of film 200. In another embodiment, compound 1036 mayalso be combined with a different polymer substrate from Table 1.

In one embodiment, the film 200 comprises a polyester substrateimpregnated with an absorbing compound 1038 selected to target lightproduced in the infrared range. In one embodiment, absorbing compound1038 is selected to target light produced in the 800-1300 nm range.Specifically, in one embodiment, absorbing compound 1038 is selected fora peak absorption in the 900-1150 nm range. One exemplary absorbingcompound 1038 is a proprietary compound produced by Adam Gates &Company, LLC, with product name IR Dye 1151, which has an absorbancepeak at 1073 nm in methyl-ethyl ketone (MEK). However, any otherexemplary absorbing compound with strong absorption in the infraredrange may also be suitable for the generation of film 200. In anotherembodiment, compound 1038 may also be combined with a different polymersubstrate from Table 1.

In one embodiment, a polymer substrate is impregnated with a combinationof compounds 1036, and 1038. In another embodiment, the polyestersubstrate is provided in a film 200 along with any one of compounds1002, 1008, 1022, 1028, 1040 or 1046. This may be, in one embodiment, incombination with any one of compounds 1004, 1010, 1018, 1024, 1030,1036, 1042 or 1048. This may be, in one embodiment, in combination withany one of compounds 1006, 1020, 1026, 1032, 1038, 1044 or 1050.

Polyethylene Example

In one embodiment, the film 200 comprises a polyethylene substrateimpregnated with an absorbing compound 1042 selected to target lightproduced in the 400-700 nm range. In one embodiment, absorbing compound1042 is selected for a peak absorption in the 600-750 nm range.Specifically, in one embodiment, absorbing compound 1042 is selected forpeak absorption in the 670-730 nm range. One exemplary absorbingcompound is a proprietary compound produced by Moleculum, withcommercial name LUM690, which has an absorption peak at 701 nm inchloroform. However, any other exemplary absorbing compound with strongabsorption in the 600-700 nm range of the visible spectrum may also besuitable for the generation of film 200. In another embodiment, compound1042 may also be combined with a different polymer substrate from Table1.

In one embodiment, the film 200 comprises a polyethylene substrateimpregnated with an absorbing compound 1044 selected to target lightproduced in the infrared range. In one embodiment, absorbing compound1044 is selected to target light produced in the 800-1100 nm range.Specifically, in one embodiment, absorbing compound 1044 is selected fora peak absorption in the 900-1100 nm range. One exemplary absorbingcompound is a proprietary compound produced by Moleculum, withcommercial name LUM1000A, which has an absorption peak at 1001 nm inchloroform. However, any other exemplary absorbing compound with strongabsorption in the infrared range may also be suitable for the generationof film 200. In another embodiment, compound 1044 may also be combinedwith a different polymer substrate from Table 1.

In one embodiment, a polymer substrate is impregnated with a combinationof compounds 1040, 1042, and 1044 such that any two of compounds 1040,1042, and 1044 are both included to form film 200. In anotherembodiment, all three of compounds 1040, 1042, and 1044 are combinedwithin a polymer substrate to form film 200.

In another embodiment, the polycarbonate substrate is provided in a film200 along with any one of compounds 1002, 1008, 1022, 1028, 1040 or1046. This may be, in one embodiment, in combination with any one ofcompounds 1004, 1010, 1018, 1024, 1030, 1036, 1042 or 1048. This may be,in one embodiment, in combination with any one of compounds 1006, 1020,1026, 1032, 1038, 1044 or 1050.

Other Exemplary Embodiments

The blue green organic absorbing compound may be selected to provide theselective transmission and/or attenuation at the desired wavelengths(e.g. by attenuating blue light relative to red light). The blue greenorganic dye may include, for example, a blue green phthalocyanine dyethat is suitable for plastic applications and provides good visibletransmittance, light stability, and thermal stability with a meltingpoint of greater than 170° C. The organic dye impregnated polycarbonatecompound may include about 0.05% to 2% absorbing compound, by weight.The blue green phthalocyanine dye may be in the form of a powder thatcan be dispersed in a molten polycarbonate during an extruding process.The blue-green dye may also be dispersed within polycarbonate resinbeads prior to an extruding process.

In another embodiment, one or more additional dyes may be dispersedwithin the film. To add infrared protection, for example, an additionalIR filtering dye may be used to provide an optical density of 9 orgreater in the IR range. One example of an IR filtering dye may includeLUM1000A. The organic dye impregnated polycarbonate mixture may includeabout 0.05% to 2% absorbing compound, by weight.

In one embodiment, an optical filter for a digital electronic device isprovided with defined electromagnetic radiation transmissioncharacteristics with selective transmission at visible wavelengths. Inone embodiment, the optical filter is engineered to block or reducetransmission of light in a plurality of wavelength ranges, for examplein both the blue light wavelength range and the red light wavelengthrange. The optical filter may be used for a variety of applicationsincluding, without limitation, a light filter, a light emission reducingfilm for electronic devices, and an LCD retardation film. The opticalfilter is made of a composition including, in one embodiment, an organicdye dispersed or impregnated in a polymer substrate such aspolycarbonate film. In another embodiment, any one or more polymersubstrates may be selected from Table 1, above.

As shown in FIG. 2A, light of wavelengths 210, 212, 214 and 218 isgenerated by the device 202. These wavelengths of light then encounterthe film 200, in one embodiment. When the wavelengths of light encounterthe film 200, the film 200 is configured to allow only some of thewavelengths of light to pass through. For example, in one embodiment asshown in FIG. 2A, UV light is substantially prevented from passingthrough the film 200. Blue-violet light is also substantially preventedfrom passing through the film 200. Blue-turquoise light 214 is at leastpartially prevented from passing through the film 200, while allowingthrough some other ranges of blue light wavelengths 216 through. Thesemay, in one embodiment, comprise wavelengths of light in the cyan colorrange. However, visible light 218, which may be safe for a user to view,is allowed to pass through the film in one embodiment. Once thewavelengths of light have encountered and passed through film 200, inone embodiment, they are then perceived by a human eye of a user usingthe device 202. In one embodiment, as shown in FIG. 2A, a region of theeye 252 is known to be highly affected by UV light, and a region of theeye 254 is known to be highly affected by blue light. By interposing afilm 200 between the device 202 and the eye 250, the light rays likelyto cause damage to the eye in regions 252 and 254 are thus substantiallyprevented from reaching the eye of a user.

FIG. 2B illustrates exemplary effectiveness wavelength absorbance rangesof a plurality of films that may be useful in one embodiment of thepresent disclosure. Film 200 may comprise, in one embodiment, a one ormore absorption compounds configured to absorb light in one or morewavelength ranges. A range of wavelengths may be blocked by a film 272,in one embodiment, where at least some rays of light in the ranges of300-400 nm are blocked from reaching the eye of a user by film 272, butthe remainder of the wavelength spectrum is substantially unaffected. Inanother embodiment, a film 274 substantially reduces light in the300-500 nm range from reaching the eye of a user, but the remainder ofthe wavelength spectrum is substantially unaffected. In anotherembodiment, a film 276 substantially reduces light in the 300-650 nmrange from reaching the eye of a user, but the remainder of thewavelength spectrum is substantially unaffected. In a furtherembodiment, film 278 reduces the amount of light in the 300-3,000 nmrange from reaching the eye of a user, but the remainder of thewavelength spectrum is substantially unaffected. Depending on differentconditions affecting a user of a device 202, different films 272, 274,276, and 278 may be applied to the user's devices 202 in order to treator prevent a medical condition.

FIG. 2C, and the examples above, illustrate a plurality of absorbingcompound spectra that may be utilized, either alone or in combination,to achieve the desired characteristics of a film, in one embodiment ofthe present disclosure. In one embodiment, one or more of the absorbingagents illustrated in FIG. 2C are impregnated within a polymer substrateto achieve the desired transmissivity.

In one embodiment, film 272 is configured to substantially block 99.9%of UV light, 15-20% of HEV light, and 15-20% of photosensitivy (PS)light. In one embodiment, film 272 comprises a UV-inhibitingpolycarbonate substrate with a thickness of at least 5 mils. In oneembodiment, the thickness is less than 10 mils. In one embodiment, film272 also comprises a UV-inhibiting additive, comprising at least 1% ofthe film 272. In one embodiment, the UV-inhibiting additive comprises atleast 2% of the film, but less than 3% of the film 272. In oneembodiment, film 272 also comprises a hard coat. In one embodiment, film272 can also be characterized as having an optical density that is atleast 3 in the 280-380 nm range, at least 0.7 in the 380-390 nm range,at least 0.15 in the 390-400 nm range, at least 0.09 in the 400-600 nmrange, and at least 0.04 in the 600-700 nm range.

In one embodiment, film 274 substantially blocks 99.9% of UV light,30-40% of HEV light, and 20-30% of PS light. In one embodiment, film 274comprises a UV-inhibiting polycarbonate substrate with a thickness of atleast 5 mils. In one embodiment, the thickness is less than 10 mils. Inone embodiment, film 274 also comprises a UV-inhibiting additive,comprising at least 1% of the film 274. In one embodiment, theUV-inhibiting additive comprises at least 2% of the film, but less than3% of the film 274. In one embodiment, the film 274 also comprisesphthalocyanine dye, comprising at least 0.0036% of the film 274. In oneembodiment, the phthalocyanine dye comprises at least 0.005%, or atleast 0.008%, but less than 0.01% of the film 274. In one embodiment,the film 274 comprises a hard coating. In one embodiment, film 274 canalso be characterized as having an optical density that is at least 4 inthe 280-380 nm range, at least 2 in the 380-390 nm range, at least 0.8in the 290-400 nm range, at least 0.13 in the 400-600 nm range, and atleast 0.15 in the 600-700 nm range.

In one embodiment, film 276 blocks 99.9% of UV light, 60-70% of HEVlight, and 30-40% of photosensitivity (PS) light. In one embodiment thefilm 276 comprises a UV-inhibiting polycarbonate substrate with athickness of at least 5 mils. In one embodiment, the thickness is lessthan 10 mils. In one embodiment, film 276 also comprises a UV-inhibitingadditive, comprising at least 1% of the film 276. In one embodiment, theUV-inhibiting additive comprises at least 2% of the film, but less than3% of the film 276. In one embodiment, the film 274 also comprisesphthalocyanine dye, comprising at least 0.005% of the film 274. In oneembodiment, the phthalocyanine dye comprises at least 0.01%, or at least0.015%, but less than 0.02% of the film 276. In one embodiment, the film276 comprises a hard coating. In one embodiment, film 276 can also becharacterized as having an optical density that is at least 4 in the280-380 nm range, at least 2 in the 380-390 nm range, at least 0.8 inthe 290-400 nm range, at least 0.13 in the 400-600 nm range, and atleast 0.15 in the 600-700 nm range.

In one embodiment, film 278 blocks 99% of UV light, 60-70% of HEV light,and 30-40% of PS light. In one embodiment, film 278 comprises aUV-inhibiting PVC film, with a thickness of at least 8 mils. In oneembodiment, the thickness is at least 10 mils, or at least 15 mils, butless than 20 mils thick. In one embodiment, film 278 also comprises anelastomer.

In one embodiment, the film is configured to substantially block 99% ofultraviolet light in the 200-315 nm range, 99% of ultraviolet light inthe 315-380 nm range, and approximately 10% of PS light (i.e., lightaround 555 nm). In one embodiment, the film is configured to allow up to65% of visible light (i.e., light ranging from 380 nm to 780 nm) passthrough. In some embodiments, the film may block various quantities ofblue light. For example, the film may have a layer that blocks 15% bluelight, a layer that blocks 30% blue light, a layer that blocks 60% bluelight, or combinations thereof. In one embodiment, film comprises aUV-inhibiting film with a thickness of 7-9 mils.

FIG. 3 depicts a graph illustrating transmission as a function ofwavelength for a variety of films that may be useful in one embodimentof the present disclosure. In one embodiment, absorption spectra 300 isassociated with a generic stock film manufactured by Nabi. Absorptionspectra 302 may be associate with another stock film provided by Nabi.Absorption spectra 304 may be associate with an Armor brand film.Absorption spectra 306 may be associated with film 272, in oneembodiment. Absorption spectra 308 may be associated with a film 276, inone embodiment. Absorption spectra 310 may be associated with a film278, in another embodiment including an elastomer. Absorption spectra312 may be associated with a film 274, in one embodiment. As shown inFIG. 3, using any of the films 272, 274, 276 or 278 produces a reductionin the absorption spectra produced by a device. For example, absorptionspectra 306 shows that a maximum transmissivity in the blue light rangeis reduced from 1.00 to 0.37, approximately. Thus, applying any of thefilms 272, 274, 276 or 278 to a device, for example device 202, mayresult in a reduction of the harmful rays of light in the knownwavelength ranges and, therefore, any of the plurality of eye relatedproblems described above.

In one embodiment, application of any one of the films shown in FIG. 3provides a measurable change in the transmission of light from a deviceto a user, as shown below in Table 3. Table 3 illustrates a percentageof energy remaining in each wavelength range after passing through theindicated applied film.

TABLE 3 ENERGY REMAINING AFTER FILM APPLICATION Nabi Wavelength careFilm Film Film Film (nm) Nabi kit Armor 272 274 276 278 UV 380-400 100%100% 76%  1%  1%  1% 92% HEV 415-455 100%  93% 88% 90% 79% 64% 33% BlueAll 400-500 100%  93% 89% 86% 78% 66% 37% Blue Cyan 500-520 100%  94%90% 86% 82% 69% 36% Green 520-565 100%  93% 88% 91% 84% 69% 36% Yellow565-580 100%  93% 88% 92% 82% 68% 33% Orange 580-625 100%  93% 88% 93%74% 64% 28% Red 625-740 100%  92% 83% 89% 45% 52% 21%

As shown in Table 3 above, any of the films described herein provide asignificant reduction in the energy remaining in a plurality ofwavelength ranges after filtering between the light produced by adevice, for example device 202, and the eye 250. Films 272, 274, 276 and278 almost completely absorb the UV light emitted by a device 202.

An organic dye impregnated film, such as film 272, 274, 276 or 278 may,in one embodiment be provided in the form of a rectangular shaped, orsquare shaped piece of film, as shown in FIG. 1C. One or more opticalfilters of a desired shape may then be cut from the film. As shown inFIG. 1A, for example, one embodiment of an optical film may include asubstantially rectangular shape for a smartphone with a circle removedfor a button of the smartphone. In another embodiment, an optical filtermay include a circle filter design, for example, to cover a digitalimage sensor in a camera of a cell phone or other electronic device. Ina further embodiment, the optical filter is provided either to amanufacturer or user in a sheet such that the manufacturer or user cancut the film to a desired size. In another embodiment, the film isprovided with an adhesive backing such that it can be sized for, andthen attached, to the desired device.

One or more additional layers of material or coating may also beprovided on a film. An additional layer of material may include a hardcoating to protect the film, for example, during shipping or use.Transmissivity can be improved by applying certain anti-reflectionproperties to the film, including at the time of application of anyother coatings, including, in one embodiment, a hard coating layer. Thefilm may also, or alternatively, have an antiglare coating applied or atack coating applied.

According to one method of manufacturing, the organic dye is produced,dispersed in the film material (e.g. polycarbonate, in one embodiment),compounded into pellets, and then extruded into a thin film usingtechniques generally known to those skilled in the art. The organic dyeimpregnated film composition may thus be provided in the form ofpellets, or in the form of an extruded film that may be provided on aroller and then cut to size depending on a specific application.

Methods for Creating a Light-Absorbing Film

FIG. 4A-4C depict a plurality of methods for generating alight-absorbing film for a device in accordance with one embodiment ofthe present disclosure. As shown in FIG. 4A, method 400 begins at block402 wherein a user obtains their device. The device may be a smartphone,laptop, tablet, or other light-emitting device, such as device 102. Theuser then obtains and applies a film, such as film 100, as shown inblock 404. The user may select a film 100 based on a particular eyeproblem, or the desire to prevent one or more particular eye-relatedproblems. After the user obtains a device, they may apply the film 100,for example, by utilizing an adhesive layer. The adhesive layer may befound on an aftermarket film, such as film 272, 274, 276 or 278.

As shown in FIG. 4B, method 410 illustrates a method for a manufacturerof a device to provide a safer screen to a user, where the safer screencomprises a film with properties such as those described above withrespect to films 272, 274, 276 and/or 278. In one embodiment, the method140 begins at block 420 wherein the manufacturer produces a screen witha combination of one or more absorbing compounds. In one embodiment, thedye may be selected from any of those described above, in order toreduce the transmission of a specific wavelength(s) of light from thedevice. The manufacturer may produce the screen such that the dyes areimpregnated within the screen itself, and are not applied as a separatefilm to the screen. The method then continues to block 422, where themanufacturer applies the screen to the device, for example using anyappropriate mechanism, for example by use of an adhesive. In oneembodiment, the method then continues to block 424 wherein themanufacturer provides the device to a user, this may comprise through asale or other transaction.

FIG. 4C illustrates a method for producing a film with specificabsorption characteristics in accordance with an embodiment of thepresent disclosure. In one embodiment, method 430 starts in block 440with the selection of wavelengths for the film to absorb, or otherwiseinhibit them from reaching the eye of a user. The method then continuesto block 442 wherein one or more absorbing compounds are selected inorder to absorb the chosen wavelength ranges, for example from Table 1above. The method then continues to block 444 wherein an appropriatefilm base is selected. The appropriate film base may be the screen of adevice. In another embodiment, the appropriate film base may be one ofany series of polymers that is compatible with the chosen dye. In oneembodiment, the user may first select an appropriate film, for examplebased on device characteristics, and then select appropriate dyes, thusreversing the order of blocks 442 and 444.

The method 430 continues in block 446 where the dye impregnated film isproduced. In one embodiment, this may involve co-extrusion of the filmwith a plurality of absorbing compounds. The film may be provided as aseries of resin beads and may be mixed with a series of resin beadscomprising the absorbing compounds desired. In an alternativeembodiment, the absorbing compounds may be provided in a liquidsolution. However, any other appropriate mechanism for producing adye-impregnated film may also be used in block 446. In one embodiment,it may also be desired for the film to have another treatment applied,for example a glare reducing or a privacy screen feature. In anotherembodiment, the film may be treated to have a hard coating, or may betreated with a tack coating. In one embodiment, any or all of thesetreatments may be provided in block 448.

In one embodiment, the method continues in block 450 where the film, forexample film 100, is provided to the device, for example device 102. Asdescribed previously, this may involve the manufacturer applying ascreen, such as screen 102, with the desired characteristics to thedevice 100 using an appropriate manufacturing procedure. It may alsocomprise providing dye impregnated aftermarket film to a user who thenapplies the film to the device, for example through either method 400and 410 described previously.

In one embodiment of a method for generating a light-absorbing film fora device, the film is produced by layering several coatings on top ofone another. More specifically the film may be comprised of severallayers such as, but not limited to, a matte topcoat, a blue dye layer, apolyethylene terephthalate (hereinafter “PET”) layer, a UV protectionlayer, a pressure sensitive adhesive (hereinafter “PSA”), and a liner.

In some embodiments, the first layer applied, which is the top layer inthe final embodiment, is a matte topcoat. The matte topcoat may providean anti-glare feature, may be oil-resistant, and may containanti-fingerprint properties. Additionally, the matte topcoat may block asmall amount of high energy visible light, such as blue light. In oneembodiment, the matte topcoat contains a haze factor, which describesthe cloudiness of the film. Ideally, the haze factor is approximately 3%so as not to impede a user's view of the device's screen. However, thehaze factor could range up to 26%. Some embodiments of the disclosedfilm do not include a matte topcoat and, instead, have no topcoat orhave a clear hard coat.

The next layer that may be applied is a blue dye. The blue dye layer mayblock various quantities of high energy visible light, such as bluelight. For example, the blue dye layer may block 30% of blue light andmay be cool blue in color. In another example, the blue dye layer mayblock 60% of blue light and may be blue green in color. The blue dyelayer, if added as the first layer, may also incorporate properties thatenable it to act as a hard coat. Some embodiments, however, will notcontain either of these blue dye layers.

Regardless of whether the blue dye layer is included, the next layer isa PET layer that blocks approximately 15% blue light. Therefore, thefilm may have a layer that blocks 30% blue light and an additional layerthat blocks 15% blue light, or it may be limited to one layer thatblocks 15% blue light. The PET layer is preferably clear and contains nocolor tint. If the film does not have a matte topcoat or a blue dyelayer, the PET layer also acts as the topcoat and may incorporateproperties that protect the remaining layers.

The next layer, which is added on to the PET layer, is a UV protectionlayer that can block at least 99% of UV light. The UV protection layermay have any of the features discussed above. On top of the UV layer, aPSA, such as a silicone PSA, may be applied. The adhesive may beconfigured so that it prevents bubbles from forming between the film andthe device during application of the film to the device. In someembodiments, the film may not include an adhesive layer. For example,applying the film to electronic devices with large screens (ex: computermonitors) using an adhesive may not be feasible and, therefore, adifferent attachment method, such as clips that clip the film to themonitor, is used.

After the adhesive or UV layer is applied, a white paper liner and/or aclear, printable liner may be applied to the top to protect thecomputer-facing layer, whether the computer-facing layer is the UV layeror the PSA. This prevents the film from attaching to any objects orbeing exposed to dirt and debris prior to attachment to an electronicdevice.

In one embodiment, for example when used as a light filter, the organicdye impregnated film allows for targeted transmission cutoff at aparticular wavelength, for example proximate the ends of the visiblewavelength spectrum. In this application, the curve should furtherincrease the overall transmission of visible wavelengths, for example,red wavelengths. The light filter may improve the true color renderingof digital image sensors, using silicon as a light absorber in oneembodiment, by correcting the absorption imbalances at red and bluewavelengths, thereby yielding improved picture quality through improvedcolor definition.

When used as an LCD retardation film, consistent with anotherembodiment, the organic dye impregnated film provides desired opticalproperties, such as 0 to 30° or 0 to 26° chief ray of incident angle andselective visible wavelengths at the 50% transmission cutoff, as well assuperior mechanical robustness at less than 0.01 mm thickness.Fundamentally, pigments tend to stay on the surface, as do some dyesgiven either the process of applying the dyes or the substrates. Thedisclosed products embody dye particles throughout the carryingsubstrate—therefore light that hits the substrate will collide with dyeparticles somewhere enroute through the substrate. Therefore, thesubstrate is designed, in one embodiment, to be safe at a minimumincidence angle of 30°. The LCD retardation film may also provide betterUV absorbance than other conventional LCD retardation films.

When used as a light emission reducing film, consistent with a furtherembodiment, the organic dye impregnated film reduces light emissionsfrom an electronic device at certain wavelengths that may be harmful toa user. The light emission reducing film may reduce peaks and slopes ofelectromagnetic emission (for example, in the blue light range, thegreen light range and the orange light range) to normalize the emissionspectra in the visible range. The emission spectra may be normalized,for example, between 0.0034-0.0038. These optical characteristics mayprovide the greatest suppression of harmful radiation in the thinnestsubstrate across the visible and near infrared range, while stillmeeting the industry standard visible light transmission requirements.

While an LCD display is illustrated in the figures, at least someembodiments of the present disclosure could apply to a device utilizinga different display generation technology, for example cathode ray tube(CRT) or light-emitting diode (LED) displays.

Incorporation into Electronic Device

As described above, in some embodiments, the protective film comprises acombination of polymer substrates and incorporates absorbing compoundsin such quantities as to absorb the harmful light produced by thedevice. However, in other embodiments, the absorbing compounds andpolymer substrates could be incorporated into the screen layers of adevice during manufacture, as illustrated in FIGS. 5C-5F and 5H, suchthat an electronic device is produced with protection from these harmfulrays built in.

The description below is designed to accompany the enclosed FIGS. 5A-5H.However, while the present embodiments are described with respect to adevice with touchscreen capability, provided through the capacity gridlayer 506, it is to be understood that at least some embodiments of thepresent disclosure could apply to a device without touch screencapability. Further, while an LCD display is shown in the figures, atleast some embodiments of the present disclosure could apply to a deviceutilizing a different display generation technology. For example,cathode ray tube (CRT) or light-emitting diode (LED) displays arepossible.

In one embodiment, as shown in FIGS. 5A and 5B, the screen of anelectronic device comprises several layers of glass and/or plastic.These layers may be configured to provide added functionality, forexample, touch-screen capability, as well as protection of the devicefrom damage by use. FIGS. 5A and 5B illustrates an exemplary screen of adigital device comprised of five layers: an LCD layer 510, a glass layer508, a capacity grid layer 506, a flexible protective cover 504, and asurface coating layer 502. The device may be a capacitive device, suchas a cellular phone or tablet with a touch-sensitive screen. The devicemay also be another form of a display device such as, but not limitedto, a television with a non-capacitive screen. Additionally, the devicemay be a form of headgear, such as glasses or contact lenses, worn by auser who is exposed to light.

In one embodiment, as shown in FIGS. 5C and 5D, one or more absorbingcompounds can be provided in a polymer layer to create an absorbing filmlayer 512 that is inserted between one of the layers comprising thescreen of an electronic device, for example, the layers previouslydescribed with regard to FIGS. 5A and 5B. As shown in FIGS. 5C and 5D,the absorbing film layer 512 could be applied between the LCD layer 510and the glass layer 508. However, in another embodiment, the absorbingfilm layer 512 could be applied between the glass layer 508 and thecapacity grid layer 506. In another embodiment, the absorbing film layer512 could be applied between the capacity grid layer 506 and theflexible protective cover 504. In another embodiment, the absorbing filmlayer 512 could be applied between the flexible protective cover 504 andthe surface coating layer 502.

In one embodiment, the absorbing film layer 512 could be applied as afilm layer inserted between any of the layers comprising the screen ofan electronic device or as a hard coating to any one of the layerscomprising the screen of an electronic device. In another embodiment,the absorbing film layer 512 could be applied as a hot coating or as apainted layer.

In a further embodiment, one or more absorbing film layers could becombined with the layers comprising the screen of an electronic device,for example, the layers previously described with regard to FIGS. 5A and5B. For example, four absorbing film layers 512 could be provided suchthat they fit between each of the five layers of the screen. However, inanother embodiment, two or three absorbing film layers 512 are providedbetween at least some of the five layers of the screen.

The absorbing film layer 512 can include at least a polymer substrate.In one embodiment, the selected polymer substrate absorbs the desiredwavelengths of light. However, in another embodiment, an additionalabsorbing compound is used for absorption of all of the desiredwavelengths of light. In a further embodiment, several absorbingcompounds can be combined with a single polymer substrate to achieve thedesired protection. FIG. 5G illustrates light waves being emitted from acomputer screen. FIG. 5H illustrates the absorbing film layer 512absorbing and, therefore, blocking those specific light waves fromreaching the user. A list of several polymer bases that could beutilized in one embodiment is provided below in Table 4.

TABLE 4 POLYMER BASES FOR ABSORBANCE FILM Polymer base CharacteristicsAcrylic impact modified, chemical resistance, superb weatherability, UVresistance and transparency Epoxy Resistivity to energy and heatPolyamide Thermoformabilty, abrasion resistance, good mechanicalproperties; High tensile strength and elastic modulus, impact and crackresistance Polycarbonate Impact strength even at low temperatures.dimensional stability, weather resistance, UV resistance, flameretardant, super-weather resistance and heat stability, opticalproperties Polyester Optics, mechanical Strength, Solvent Resistant,Tear and puncture resistant Co-polyester printable, scratch hardness(PETG, PCTG) Polyethylene Geomembrane windows, global recylability, goodmoisture barrier, clarity, strength, toughness Polyolefin Good chemicalresistance Polypropylene High impact and puncture resistance, excellentextensibility Polystyrene good printablity, high impact resistance, gooddimensional stability, easy to thermoform Polysolfone high strength,amorphous thermoplastic, clarity and toughness, high-heat deflectiontemperature, excellent thermal stability, excellent hydrolitic stabilityPolyurethane Excellent laminated transparency, microbial resistance, UVstability, contains adhesion promoter, medium Durometer, Medium Modulus,Excellent Cold impact Polyvinyl Weathering resistance, abrasionresistance, chemical resistance, flow Chloride characteristics, stableelectrical properties Styrene superior mechanical strength, chemicalresistance, heat resistance, Acrylonitrile durability, simplicity ofproduction, recyclability, impact strength, heat resistance, good impactresistance, excellent hygiene, sanitation and safety benefits.

In one embodiment, one of the polymers selected from Table 4 is combinedwith one or more absorbing compounds in the desired target range, asillustrated in Table 5 below. The absorbing compounds listed in Table 5are some examples of absorbing compounds selectable for desiredprotection in given wavelength ranges.

TABLE 5 ABSORBING MATERIALS AND WAVELENGTH RANGES Exemplary Polymer260-400 nm 400-700 nm Infrared Substrate Target Range Target RangeTarget Range Polycarbonate Tinuvin ® ABS 668 NIR1002A PVC DYE VIS 347ADS640PP NIR1031M Epoxy UVA290A VIS675F NIR1072A Polyester VIS530A DYEVIS 670 Adam Gates IR 1422 Polyethylene ABS 400 ABS 691 Adam Gates IR1151 Polyamide phthalocyanine LUM690 LUM1000A FHI 6746 LUM995 MoleculumDYE 690

The absorbing film layer 512, in one embodiment, has a slight color tintas a result of, at least in part, the absorbing compound selected, andworks as a filter to reduce light emission from the screen. In oneembodiment, under a CIE light source D65, the absorbing film layer 512,having a 7.75 mil thickness, is a light blue-green color with (L, a, B)values of (90.24, −12.64, 3.54) and (X-Y-Z) values of (67.14, 76.83,78.90) respectively. In another embodiment, the absorbing film layer 512appears light due to reduced loading.

In one embodiment, the polymer substrate and absorbing compound orcompounds are mixed and extruded as pellets that can then be molded intothe absorbing film layer 512. Alternatively, they can be headed for ahot coat. In another embodiment, the polymer substrate and one or moreabsorbing compounds are extruded or produced as part of any of thelayers of the screen of the device.

In one embodiment, between one or more of each of the layers of a screenof an electronic device, an adhesive compound may be used to ensure thatthe layers fit together. The adhesive compound may further provide aseal between the layers. Therefore, instead of providing protection fromharmful light wavelengths as an additional film layer within the screen,the protection may be provided through the adhesive used to bind thelayers of the screen.

FIGS. 5E and 5F illustrate an exemplary screen of a digital deviceincorporating a light absorbing adhesive 514 that haswavelength-absorbing properties. In one embodiment, as shown in FIGS. 5Eand 5F, one or more absorbing compounds are provided in a lightabsorbing adhesive 514 coating a top or bottom side of the layerspreviously described with regard to FIGS. 5A and 5B. For example, thelight absorbing adhesive 514 could be applied, as shown in FIGS. 5E and5F, as the adhesive bonding the capacity grid layer 506 to the flexibleprotective cover 504. However, in another embodiment, the lightabsorbing adhesive 514 could be applied as the adhesive bonding the LCDlayer 510 to the glass layer 508. In another embodiment, the lightabsorbing adhesive 514 could be applied as the adhesive bonding theglass layer 508 to the capacity grid layer 506. In another embodiment,the light absorbing adhesive 514 could be applied such that it bonds theflexible protective cover 504 to the surface coating layer 502.

In a further embodiment, one or more absorbing compounds could be usedas part of the adhesive bonding between each of the five layers. Forexample, the light absorbing adhesive 514 could be the sole adhesiveused between the five layers. However, in another embodiment, the lightabsorbing adhesive 514 can be used between two or three of the layers ofthe screen. In one embodiment, the absorbing compound selected is basedon a selected range of light wavelengths to block. For example, theabsorbing compound selected may be from any of the columns 2-4 of Table5.

The light absorbing adhesive 514 can include at least a polymersubstrate. In one embodiment, the selected polymer substrate absorbs thedesired wavelengths of light. However, in another embodiment, anadditional absorbing compound is used for absorption of all of thedesired wavelengths of light. In a further embodiment, several absorbingcompounds can be combined with a single polymer substrate to achieve thedesired protection.

In one embodiment, a silicone adhesive can be used with any of theabsorbing compounds listed in columns 2-4 of Table 5. In one embodiment,a pressure-sensitive adhesive can be used with any of the absorbingcompounds listed in columns 2-4 of Table 5. In another embodiment, a hotmelt adhesive can be used with any of the absorbing compounds listed incolumns 2-4 of Table 5. In a further embodiment, an acrylic adhesive canbe used with any of the absorbing compound listed in columns 2-4 ofTable 5.

In one embodiment, dissolving the desired absorbing compound in aketone-based solvent, preferably a methyl-ethyl-ketone, can create theadhesive. The dissolved absorbing compound can then be missed with thedesired adhesive compound. For example, in one embodiment, apressure-sensitive adhesive can be combined with an absorbing compounddissolved in a ketone-based solvent. In at least one embodiment, themethod includes at least one filtering step to remove un-dissolvedabsorbing compounds. In another embodiment, the method includes theaddition of extra solvent to re-dissolve absorbing compounds causingcaking along the process.

An adhesive layer, in one embodiment, has a slight color tint, as aresult of, at least in part, the absorbing compound selected, and worksas a filter to reduce light emission from the screen. In one embodiment,under a CIE light source D65, the adhesive layer, having a 7.75 milthickness, is a light blue-green color with (L, a, B) values of (90.24,−12.64, 3.54) and (X-Y-Z) values of (67.14, 76.83, 78.90) respectively.In another embodiment, the adhesive layer appears lighter due to reducedloading.

In some embodiments, the absorbing compounds can be provided in one ormore polymer substrates to be integrated with the electronic screen'spolarizing filter. For example, in the case of an electronic screen withan LCD screen, the screen has two polarizing filters and the absorbingcompounds can be coated over one of the screen's polarizing filters. Inthe case of a coating, the absorbing compounds can be provided in apolymer substrate that enables the polarizer filter to be laminated withthe absorbing compounds. In another example, the absorbing compounds canbe incorporated directly into one of the two polarizing filters.

As described above, the absorbing compounds ideally block only a portionof the wavelength ranges for each color, so that each hue is stillvisible to the individual viewing the screen of the electronic device.Therefore, in embodiments wherein the absorbing compounds are integratedinto an electronic devices screen, colors that have portions of theirwavelengths blocked by the disclosed technology can be amped up so thatthe small range allowed through the absorbing compounds is brighter.

Incorporation into Virtual Reality Headset

While other embodiments have been described with respect to a devicewith touchscreen capability provided through the capacity grid, it is tobe understood that at least some embodiments of the present disclosurecould apply to a device without touch screen capability. For example, inone embodiment, the present disclosure could be applied to, orintegrated into, a virtual reality headset device, as illustrated inFIGS. 6A-6C, or another type of head-mounted glass device configured toabsorb wavelengths of light generated by a light source.

Virtual reality (VR) headsets are pieces of headgear that users can wearover their eyes for an immersive audiovisual experience. Morespecifically, VR headsets provide a screen that is inches away from auser's face. Additionally, VR headsets shield ambient light and preventit from intruding into the user's field of vision. Due to the proximityof screens, and therefore UV and blue light, to users' eyes, VR headsetspresent unique sets of risks to users. The disclosed technology isuniquely useful with VR headsets because it can block these harmfulwavelengths. In some embodiments, because a VR headset blocks ambientlight from interfering with the screen, the pigmentation or chemicalstructure used in the light absorbent material may interfere with theuser's color experience and, therefore, the light absorbing materialsused for a VR headset may vary from the above-described embodiments.

Some virtual reality headsets include glasses, frames, or units combinedwith headphones or another listening device and can receive a mobilephone that acts as the screen. The phone can snap into the headset and auser can utilize a mobile application on the phone, as described in U.S.Pat. No. 8,957,835 (the '835 patent). FIG. 4 of the '835 patentillustrates one type of phone-based virtual reality headset. The presentdisclosure could be used in conjunction with this virtual realityheadset, as illustrated in FIG. 6A. In this embodiment, thelight-absorbing layer 602 can be built into the frame of the virtualreality headset in front of the phone so that, when the light istransmitted from the phone, it must pass through the light-absorbinglayer 602 before proceeding through the rest of the headset and on tothe user's eyes. The light-absorbing layer 602 can embody any of theseveral properties described above.

Instead of using a phone as a screen, other virtual reality headsetshave a built in screen panel. For example, the Oculus Rift, developed byOculus VR, uses an organic light-emitting diode (OLED) panel for eacheye. In these virtual reality headsets, the light-absorbing layer 602can be included in front of the light display panel, as illustrated inFIGS. 6B and 6C. The light-absorbing layer 602 may be one continuouslayer that covers both eyes. In another embodiment, there may be twolight-absorbing layers 602, one for each eye. In some embodiments, eachlight-absorbing layer 602 is a flat panel. In other embodiments, eachlight-absorbing layer 602 is curved around the interior of the headset.

Display System

FIG. 7 is a schematic cross-sectional view of an example display system700 with which systems of the present disclosure may be beneficiallyemployed. Such a display system 700 may be used, for example, in aliquid crystal display (LCD) monitor, LCD-TV, handheld, tablet, laptop,or other computing device. Display system 700 of FIG. 7 is merelyexemplary, however, and the systems of the present disclosure are notlimited to use with systems like or similar to system 700. The systemsof the present disclosure may be beneficially employed in othervarieties of displays systems that do not necessarily include liquidcrystal display technology.

The display system 700 can include a liquid crystal (LC) panel 750 andan illumination assembly 701 positioned to provide illumination light tothe LC panel 750. The LC panel 750 typically includes a layer of LC 752disposed between panel plates 754. Plates 754 can include electrodestructures and alignment layers on their inner surfaces for controllingthe orientation of the liquid crystals in the LC layer 752. Theseelectrode structures can be arranged so as to define LC panel pixels. Acolor filter can also be included with one or more of the plates 752 forimposing color on the image displayed by the LC panel 750.

The LC panel 750 can be positioned between an upper absorbing polarizer756 and a lower absorbing polarizer 758. The absorbing polarizers 756,758 and the LC panel 750 in combination can control the transmission oflight from the illumination assembly 701 to a viewer, the viewergenerally being positioned toward the top of FIG. 7 and lookinggenerally downward (relative to FIG. 7) at display system 700. Acontroller 704 can selectively activate pixels of the LC layer 752 toform an image seen by the viewer.

One or more optional layers 757, can be provided over the upperabsorbing polarizer 756, for example, to provide optical function and/ormechanical and/or environmental protection to the display.

The illumination assembly 701 can include a backlight 708 and one ormore light management films 740 positioned between the backlight 708 andthe LC panel 750. The backlight 708 of the display system 700 caninclude a number of light sources 712 that generate the light thatilluminates the LC panel 750. Light sources 712 can include any suitablelighting technology. In some embodiments, light sources 712 can belight-emitting diodes (LEDs), and more particularly, can be white LEDs.Backlight 708 as illustrated can be a “direct-lit” backlight in which anarray of light sources 712 are located behind the LC panel 750substantially across much or all of the panel's area. Backlight 708 asillustrated is merely schematic, however, and many other other backlightconfigurations are possible. Some display systems, for example, caninclude a “side-lit” backlight with light sources (such as LEDs) locatedat one or more sides of a light-guide that can distribute the light fromthe light sources substantially across much or all of the area of LCpanel 750.

In some embodiments, the backlight 708 emits generally white light, andthe LC panel 750 is combined with a color filter matrix to form groupsof multicolored pixels so that the displayed image is polychromatic.

The backlight 708 may also include a reflective substrate 702 forreflecting light from the light sources 712 propagating in a directionaway from the LC panel 750. The reflective substrate 702 may also beuseful for recycling light within the display system 700.

An arrangement 740 of light management films, which may also be referredto as a film stack, a backlight film stack, or a light management unit,can be positioned between the backlight 708 and the LC panel 750. Thelight management films 740 can affect the illumination light propagatingfrom the backlight 708 so as to improve the operation of the displaysystem 700. The light management unit 740 need not necessarily includeall components as illustrated and described herein.

The arrangement 740 of light management films can include a diffuser720. The diffuser 720 can diffuse the light received from the lightsources 712, which can result in increased uniformity of theillumination light incident on the LC panel 750. The diffuser layer 720may be any suitable diffuser film or plate.

The light management unit 740 can include a reflective polarizer 742.The light sources 712 typically produce unpolarized light, but the lowerabsorbing polarizer 758 only transmits a single polarization state;therefore, about half of the light generated by the light sources 712 isnot transmitted through to the LC layer 752. The reflective polarizer742, however, may be used to reflect the light that would otherwise beabsorbed in the lower absorbing polarizer 758. Consequently, this lightmay be recycled by reflection between the reflective polarizer 742 andunderlying display components, including the reflective substrate 702.At least some of the light reflected by the reflective polarizer 742 maybe depolarized and subsequently returned to the reflective polarizer 742in a polarization state that is transmitted through the reflectivepolarizer 742 and the lower absorbing polarizer 758 to the LC layer 752.In this manner, the reflective polarizer 742 can be used to increase thefraction of light emitted by the light sources 712 that reaches the LClayer 752, thereby providing a brighter display output. Any suitabletype of reflective polarizer may be used for the reflective polarizer742.

In some embodiments, a polarization control layer 744 can be providedbetween the diffuser plate 720 and the reflective polarizer 742. Thepolarization control layer 744 can be used to change the polarization oflight that is reflected from the reflective polarizer 742 so that anincreased fraction of the recycled light is transmitted through thereflective polarizer 742.

The arrangement 740 of light management films can also include one ormore brightness enhancing layers. A brightness enhancing layer caninclude a surface structure that redirects off-axis light in a directioncloser to the axis of the display. This can increase the amount of lightpropagating on-axis through the LC layer 752, thus increasing thebrightness of the image seen by the viewer. One example of a brightnessenhancing layer is a prismatic brightness enhancing layer, which has anumber of prismatic ridges that redirect the illumination light throughrefraction and reflection. Examples of prismatic brightness enhancinglayers include BEF prismatic films available from 3M Company. Othervarieties of brightness enhancing layers can incorporate non-prismaticstructures.

The exemplary embodiment illustrated in FIG. 7 shows a first brightnessenhancing layer 746 a disposed between the reflective polarizer 742 andthe LC panel 750. A prismatic brightness enhancing layer typicallyprovides optical gain in one dimension. An optional second brightnessenhancing layer 746 b may also be included in the arrangement 740 oflight management layers, having its prismatic structure orientedorthogonally to the prismatic structure of the first brightnessenhancing layer 746 a. Such a configuration provides an increase in theoptical gain of the display system 700 in two dimensions. In otherexemplary embodiments, the brightness enhancing layers 746 a, 746 b maybe positioned between the backlight 708 and the reflective polarizer742.

The different layers in the light management unit 740 can be freestanding. In other embodiments, two or more of the layers in the lightmanagement unit 740 may be laminated together. In other exemplaryembodiments, the light management unit 740 may include two or moresubassemblies.

It is to be understood that as a schematic diagram, the components ofdisplay system 700 are not illustrated to scale, and generally are shownwith greatly exaggerated thickness (along the up-down direction of FIG.7) compared to their lateral extent (along the left-right direction).Many elements of display system 700, including (but not necessarilylimited to) 702, 720, 742, 744, 746 a, 746 b, 752, 754, 756, and 757 canextend in two dimensions generally orthogonal to their thickness (i.e.,perpendicular to the plane of FIG. 7) over an area approximately equalto a viewable area of the display, which may be referred to as a“display area.”

Returning to backlight 708, in some embodiments light sources 712 canemit significant amounts of light in potentially harmful wavelengthranges, such as UV and blue light ranges (particularly below about 455nm). In a display system 700 that does not include systems of thepresent disclosure, significant amounts of such potentially harmfullight can be emitted by the display system 700 toward a user (upwardrelative to FIG. 7). In this context a “significant” amount of light canmean an amount of light that may result in deleterious health effectsfor a display user. In view of this hazard, the present disclosureprovides systems for reducing the amount of harmful blue light emittedfrom display systems such as system 700.

In some approaches to mitigating the hazards of blue light emissionsfrom electronic device displays, absorbing materials can be used toreduce the amount of light in particular wavelength ranges (such as UVand blue light wavelength ranges) that reach users' eyes. Some of thesesolutions are described in U.S. Nonprovisional application Ser. No.14/719,604, filed May 22, 2015 and titled LIGHT EMISSION REDUCING FILMFOR ELECTRONIC DEVICES, U.S. Provisional Application No. 62/002,412,filed May 23, 2014 and titled LIGHT EMISSION REDUCING FILM FORELECTRONIC DEVICES, U.S. Provisional Application No. 62/175,926, filedJun. 15, 2015 and titled LIGHT EMISSION REDUCING FILM FOR ELECTRONICDEVICES, U.S. Provisional Application No. 62/254,871, filed Nov. 13,2015 and titled LIGHT EMISSION REDUCING COMPOUNDS FOR ELECTRONICDEVICES, U.S. Provisional Application No. 62/255,287, filed Nov. 13,2015 and titled LIGHT EMISSION REDUCING FILM FOR VIRTUAL REALITYHEADSET, U.S. Provisional Application No. 62/322,624, filed Apr. 14,2016 and titled LIGHT EMISSION REDUCING FILM FOR ELECTRONIC DEVICES,U.S. Provisional Application No. 62/421,578, filed Nov. 14, 2016 andtitled LIGHT EMISSION REDUCING COMPOUNDS FOR ELECTRONIC DEVICES,International Application under the Patent Cooperation Treaty No.PCT/US2015/032175, filed May 22, 2015 and titled LIGHT EMISSION REDUCINGFILM FOR ELECTRONIC DEVICES, and International Application under thePatent Cooperation Treaty No. PCT/US2016/037457, filed Jun. 14, 2016 andtitled LIGHT EMISSION REDUCING COMPOUNDS FOR ELECTRONIC DEVICES, whichare incorporated by reference limited such that no subject matter isincorporated that is contrary to the explicit disclosure herein.

Incorporation of Light Absorbing Materials into Display Systems

In some embodiments of systems of the present disclosure, lightabsorbing materials can be located in any suitable location away fromlight sources of the display. In some embodiments, light absorbingmaterials can be included in, on, or with one or more films of lightmanagement films 740, and or another film or films not illustrated inFIG. 7. In general, light absorbing materials can re-emit light withdifferent directionality and/or polarization compared with lightabsorbed by the light absorbing materials. Accordingly, in someembodiments light absorbing materials can be included below (relative tothe orientation of FIG. 7) one or more of reflective polarizer 742and/or brightness enhancement layers 746 a, 746 b, such that re-emittedlight passes through films 742, 746 a, and 746 b (if such films arepresent in the display system) before exiting the display toward a user.However, this is not limiting and light absorbing materials potentiallycan be located in, or, or with any component of light management films740.

In some embodiments of systems of the present disclosure, lightabsorbing materials can be included in, on, or with a display layerbetween LC layer 752 and a user, such as layer 757 of FIG. 7.

In some embodiments of systems of the present disclosure, lightabsorbing materials can be included in, on, or with reflective substrate702.

In some embodiments of systems of the present disclosure, lightabsorbing materials can be distributed substantially about an entirearea corresponding to the display area of a display when included orprovided in, on, or with a film of light management films 740, reflector702, or another layer, such as layer 757. In some such embodiments,light absorbing materials can be distributed substantially uniformlyover such an area.

Light absorbing materials can be included or provided in, on, or with afilm of light management films 740, reflector 702, or another layer,such as layer 757, in any suitable manner. In some embodiments, lightabsorbing materials can be extruded or cast with a film, In someembodiments, light absorbing materials can be coated onto a film. Insome embodiments, light absorbing materials can be provided in or withan adhesive used to bond or laminate one or more layers of a displaysystem, such as any suitable layers or films of display system 700. Suchan adhesive incorporating light absorbing materials can be substantiallyoptically clear, exhibiting negligible scattering of light transmittedthrough the adhesive, other than redirection of light associated withabsorption and re-emission by light absorbing materials.

In some embodiments, light absorbing materials can be solubly orinsolubly distributed or dispersed throughout a material that is acomponent or precursor of any suitable film or layer of display system700, such as a polymer resin or an adhesive. In some embodiments, lightabsorbing materials can comprise nano-particles, some which may beinsoluble in polymers and commonly used solvents. While homogeneousdistribution may be more easily achieved in some systems with solublelight absorbing materials, even heterogeneous distribution can beachieved with insoluble light absorbing materials with appropriatehandling during manufacture.

Retina Protection Factor (RPF)

Blue Light or high energy visible light is recognized by a number ofsources as potentially harmful to eye health. The toxicity of this BlueLight Hazard as outlined in the ICNIRP guidelines published in HealthPhysics 105(1): 74-96; 2013, has been adopted in the ANSI Z80.3 andCE-166 Standards, and is summarized below in Table 6.

TABLE 6 nm *BLH-ANSI Z80.3 Table far UV 200-315 0 Near UV 315-380 0 3800.006 385 0.012 390 0.03 395 0.05 400 0.1 405 0.2 410 0.4 415 0.8 4200.9 425 0.95 430 0.98 **Peak 435 1 **Peak 440 1 445 0.97 450 0.94 4550.9 460 0.8 465 0.7 470 0.62 475 0.55 480 0.45 485 0.4 490 0.22 495 0.16500 0.1 (*BLH = Blue light Hazard ANSI = American National Standards)

The RPF (retina protection factor) value is based on the percentreduction due to the use of a selective filtering of the most toxic wavelengths of Blue Light as outlined in table 6 above for the Blue LightHazard, BLH. The luminance vs. wave-length of a light source iscalculated using a spectrophotometer. Those emissions are thenmultiplied by the factors for toxicity in the table above. The sum ofthose values over the range of the visible spectrum is then the weightedtoxicity level for that light source according to the following equationwith definitions:Total Blue Light Hazard=ΣL(λ)×BLH(λ)×(Δλ)

-   BLH(λ). The Blue light hazard toxicity weighting function in Table 6    above.-   L(λ)=Luminance or Emission for the monitor in candela/meter squared-   (Δλ)=the bandwidth over which the toxicity rating is associated (5    nm)

A candidate film is then applied to the light source (display) and themeasurement and the toxicity of the light is again calculated by thesame procedure. The reduction of the toxicity is then expressed as a %reduction(100×[Toxicity without film−Toxicity with film]/Toxicity withoutfilm)=(x) % Reduction=RPF(x)436 Dye−Low, Med and High Concentration−Spectral Scan, RPF Value, Changein Luminance, Gamut, RGB Location change and delta E's

Display manufacturers, when specifying a blue light reduction film, maywish to balance the reduction in Blue Light Toxicity with minimizing theimpact on color and luminance of their particular display.

Notch Absorbers and Multiple-Notch Filters

Some embodiments described herein make use of “notch” absorbing dyesthat minimize negative impacts on color and luminance while morespecifically targeting particular hazardous wave-lengths for blue light.“Notch” absorbers for the purpose of this technology can be defined asabsorbers with an absorption band width of 50 nm or less at theirrespective full width half maximum (FWHM). In some examples, a notch canhave a FWHM of less than about 40 nm, less than about 30 nm, less thanabout 20 nm, and/or less than about 10 nm. While examples herein maydescribe the use of notch absorption dyes, it should be recognized thatother light filtering mechanisms other than absorptive dyes can be usedto filter light in particular wavelength ranges, including notch bands.For example, multi-layer interference filters can be precisely tailoredto affect narrow wavelength ranges.

In this disclosure, we describe concepts for double-notch filters forelectronic devices that filter light from both the blue spectrum as wellas the red spectrum. Either or both absorption regions can achieved withabsorption dyes, but the concept is not limited to such absorption dyes.Any examples specifically employing a particular technology orcombination of technologies (for example, absorptive dyes in tworegions) can be generalized to include any combination of lightfiltration technologies capable of effecting the same net resultantfiltration.

One reason for adding red light filtration/absorption to a filter isthat a single notch blue filtering/absorbing filter, by removing bluelight, can cause the resulting filtered light to shift to a lower colortemperature (compared to the spectrum of light input to the filter).This can be undesirable for at least color management reasons. By alsoremoving a narrow-band portion of light in a red part of the spectrum,the color temperature can be shifted back to a higher value, which maybe more desirable for color management.

In some examples, a double-notch filter can, using input light from aconventional LED-backlit LCD display, output light that can be measuredas substantially satisfying criteria for a D65 white point. In someexamples, a double-notch filter can output light that can be measured asnearly satisfying criteria for a D65 white point, to within +/− 500Kelvin. In some examples, a double-notch filter can output light thatcan be measured as nearly satisfying criteria for a D65 white point, towithin +/− 1000 Kelvin.

FIG. 8 shows spectra for changing concentrations of a narrow notch bluelight filtering dye of the present disclosure.

Table 7 illustrates how balance can be achieved when filtering bluelight and shows how changes in concentration impact RPF value and changein color temperature, CCT. The second half of the table (the second setof three rows) shows the use of a red-absorbing “color correction dye”(a notch absorption dye with a peak absorption at about 630 nm) toreduce the absolute change from 999 to 47, while the concentration ofblue absorbing dye is held constant. This can be balanced by the changesin correlated color temperature (CCT), luminance, and White Point color(as measured by Delta E) that are considered acceptable (by, forexample, manufacturers, users, and any other interested parties). FIG. 9illustrates the effects of varying concentrations of color correctiondye with blue-light absorbing dye concentration held constant,corresponding to the last three rows of Table 7.

TABLE 7 RPF and Color Impact of Dye concentration. RPF Ratio of Value %Change Color (Blue Change in in Concentration correction Light colorLuminance of blue light dye to % of weighted temperature cd/m2 DeltaBase Film absorbing dye Blue-light “blue” by (from (from E(2000) %Change (arbitrary absorbing light toxicity oringinal original for Whitein units) dye reduced level) ~6825K) 298 Point Luminance 1 0 57% 61%−1921 −14.4% 3.86 −13.40% 0.25 0 32% 33% −999 −13.8% 1.76 −13.40% 0.06250 20% 20% −389 −13.4% 0.7 −13.40% 0.25 2:1 32% 34% 47 −19.5% 2.59−13.40% 0.25 1:1 32% 34% −424 −16.8% 2.2 −13.40% 0.25 1:2 32% 34% −695−15.4% 1.98 −13.40%

For comparative purposes, FIG. 10 illustrates impact of a broad-band(not narrow notch) blue-light absorbing dye, without use of a colorcorrection dye. Table 8 shows a comparison of the “notch” dye and thebroader absorption dye on the RPF and Color Criteria. The benefit of thenarrow notch dye is most significant with higher RPF protection valuesas well as higher transmission film. At the highest levels of protectionand with higher transmission film, there is a 50% greater loss ofluminance (15% for the broader absorber vs. 10% for the narrow notchdye).

TABLE 8 Comparison with “Notch” and broader absorption dyes on RPF andColor Impact of Dye concentration. Change in % Change in RPF Value colorLuminance Base Concentration % of (Blue Light temperature cd/m2 Film %of blue light “blue” weighted (from (from Change absorbing light bytoxicity oringinal original in dye reduced level) 6826K) 298 LuminanceUV Narrow 1 57% 61% −1921 −14.4% −13.40% Absorber Notch 0.25 32% 33%−999 −13.8% −13.40% Film Blue Light 0.0625 20% 20% −389 −13.4% −13.40%Absorber Broad 0.91 61% 60% −2207 −18.8% −13.40% Blue Light 0.25 31% 31%−1012 −15.1% −13.40% Absorber 0.667 20% 20% −405 −13.8% −13.40% HigherNarrow 1 56% 61% −1978 −10.1%  −9.06% Trans. Notch 0.25 28% 30% −992 −9.4%  −9.06% Base Blue Light 0.625 18% 16% −381  −9.1%  −9.06% FilmAbsorber Broad 0.91 61% 61% −2302 −15.1%  −9.06% Blue Light 0.25 31% 31%−1177 −11.1%  −9.06% Absorber 0.667 16% 16% −396  −9.4%  −9.06%

The dye concentration(s) can be adjusted based on a change in the basefilm (substrate) for incorporation of the dye or the coating containingthe dye.

TABLE 9 Illustrates optimization when using different films withdifferent transmission levels. Ratio of RPF Color Value % correctiontemperature Change in Change light Light color in Delta dye to % ofweighted Luminance cd/m2 E(2000) Base Film Concentration Blue-light“blue” by (from (from for % Change of blue light absorbing (Bluetoxicity oringinal original White in absorbing dye dye reduced level)~6825K) 298 Point Luminance 0.25 2:1 32% 34% 47 −19.5% 2.59 −13.40% 0.251:1 32% 34% −424 −16.8% 2.2 −13.40% 0.25 1:2 32% 34% −695 −15.4% 1.98−13.40% 0.25 0 32% 33% −999 −13.8% 1.76 −13.40% 0.25 2:1 28% 30% 55−15.4% 2.66  −9.06% 0.25 1:1 28% 30% −416 −12.7% 2.26  −9.06% 0.25 1:228% 30% −689 −11.1% 2.02  −9.06% 0.25 0 28% 30% −992  −9.4% 1.87  −9.06%

The dye concentrations for both the “notch” dye as well as the colorcorrection dye can be adjusted for optimum performance based on theparticular display and the LED's used in the back-light. Table 10demonstrates two different scenarios. FIG. 11 shows the optimizationdone for LED Back-light “B” similar to that shown in FIG. 9.

TABLE 10 Demonstrates need to optimize the film parameters based onback-light emission of the display. Change in RPF color Ratio of Valuetemperature % Change Color (Blue (from in correction Lighted oringinalLuminance Delta dye to % of weighted ~6825K and cd/m2 E(2000) BaseConcentration Blue-light “blue” by ~6900K for (from for Film % of bluelight absorbing light toxicity A and B original White Change inabsorbing dye dye reduced level) respectively) 298 Point Luminance LED0.25 2:1 32% 34% 47 −19.5% 2.59 −13.40% Back- 0.25 1:1 32% 34% −424−16.8% 2.2 −13.40% light 0.25 1:2 32% 34% −695 −15.4% 1.98 −13.40% A0.25 0 32% 33% −999 −13.8% 1.76 −13.40% LED 0.33 1:1 28% 30% 1026 −21.0%3.37 −13.40% Back- 0.33 1:2 28% 30% 134 −17.9% 2.55 −13.40% light 0.331:4 28% 30% −357 −16.0% 2.08 −13.40% B 0.33 0 28% 30% −876 −13.7% 1.67−13.40%

While the principles of the invention have been described herein, it isto be understood by those skilled in the art that this description ismade only by way of example and not as a limitation as to the scope ofthe invention. Other embodiments are contemplated within the scope ofthe present disclosure in addition to the exemplary embodiments shownand described herein. Modifications and substitutions by one of ordinaryskill in the art are considered to be within the scope of the presentdisclosure.

What is claimed is:
 1. A light-filtering film for a screen of a device comprising: a polymer substrate; a first absorbing compound combined with the polymer substrate, the first absorbing compound absorbing blue light in a blue notch band having a full-width half-maximum of not greater than about 50 nm; and a second absorbing compound combined with the polymer substrate, the second absorbing compound absorbing red light in a red notch band having a full-width half-maximum of not greater than about 50 nm, wherein the first absorbing compound comprises an absorption that has a maximum absorbance peak from about 420 nm to about 445 nm, and the second absorbing compound comprises an absorption that has a maximum absorbance peak from about 640 nm to about 700 nm.
 2. A light-filtering film according to claim 1, further comprising a third absorbing compound combined with the polymer substrate, the third absorbing compound absorbing light absorbing light in a band between the blue notch band and the red notch band.
 3. A light-filtering film according to claim 2, wherein the third absorbing compound comprises an absorption that has a maximum absorbance peak from about 565 nm to about 600 nm.
 4. A light-filtering film according to claim 1, wherein the polymer substrate comprises an acrylic polymer, an epoxy polymer, a polyamide, a polycarbonate, a polyester, a co-polyester of PETG and PCTG, a polyethylene, a polyolefin, a polypropylene, a polystyrene, a polysulfone, a polyurea, a polyvinyl chloride, or a styrene acrylonitrile.
 5. A light-filtering film according to claim 1 comprising at least one of an antiglare coating, a hard coating, and a tack coating.
 6. A light-filtering film according to claim 1, wherein the film is applied to an electronic device.
 7. A light-filtering film according to claim 6, wherein the electronic device comprises at least one of an LED (light-emitting diode), LCD (liquid-crystal display), computer monitor, equipment screen, television, tablet, or cellular phone.
 8. A light-filtering film according to claim 6, wherein the electronic device comprises a capacitive touch screen.
 9. A light-filtering film according to claim 1, wherein the first absorbing compound comprises a blue or blue-green organic dye dispersed therein.
 10. A light-filtering film according to claim 9, wherein the organic dye comprises a blue-green phthalocyanine dye.
 11. A light-filtering film according to claim 9, wherein the organic dye comprises between about 0.05 percent to about 2.00 percent of the polymer substrate by weight.
 12. A light-filtering film according to claim 1, wherein the filter can output light that measures to within 1000 Kelvin of a D65 white light.
 13. A light-filtering film according to claim 1, wherein the first absorbing compound, the second absorbing compound, or both are impregnated into the polymer substrate.
 14. A light-filtering film according to claim 1 comprising an adhesive.
 15. A light-filtering film according to claim 14, wherein the adhesive comprises a pressure-sensitive adhesive.
 16. A light-filtering film according to claim 1, wherein the first absorbing compound and the second absorbing compound are provided in combination so that, for light produced by the screen transmitted through the light-filtering film, correlated color temperature is within about 1000 Kelvin of correlated color temperature for light produced by the screen that is not transmitted through the light-filtering film. 